|Born||24 January 1998|
|Highest ranking||71 (July 2018)|
|78 (as of 4 May 2021)|
2016 International Championship
|Best ranking finish||Semi-finals (2017 Indian Open)|
Prior to turning professional, Xu began playing in minor-ranking Asian Players Tour Championship from age 15, and his first appearance at a ranking event was in the wildcard round of the 2014 Shanghai Masters where he was whitewashed 5-0 by Ryan Day. He also made a wildcard appearance at the 2016 World Open where he defeated veteran James Wattana 5-3 or progress to the last 64, where he lost in the next round against Daniel Wells. He made a further appearance at the 2016 Shanghai Masters wildcard round where he lost 5–1 to Michael Holt. He then won two matches at the 2016 International Championship, defeating professionals Wang Yuchen at the wildcard stage, and two-time world champion Mark Williams in the last 64 before losing to Wattana in the last 32. He lost out in the first round of qualifying for the 2017 World Snooker Championship, losing 10–5 to Rod Lawler.
In August 2016 Xu won the 2016 IBSF World Under-21 Snooker Championship by defeating Alexander Ursenbacher 6-5 after being 5-3 down. This victory earned him a two-year World Snooker Tour card. His first professional match was in qualifying for the 2017 Riga Masters where he lost 4–2 to Robbie Williams.
Performance and rankings timeline
|European Masters||Tournament Not Held||A||LQ||LQ||LQ||1R|
|English Open||Tournament Not Held||A||1R||2R||2R||3R|
|Championship League||Non-Ranking Event||RR|
|Northern Ireland Open||Tournament Not Held||A||1R||1R||1R||2R|
|Scottish Open||Tournament Not Held||A||4R||1R||1R||1R|
|World Grand Prix||NH||NR||DNQ||DNQ||DNQ||DNQ||DNQ||DNQ|
|Gibraltar Open||Not Held||MR||A||1R||1R||2R||1R|
|WST Pro Series||Tournament Not Held||RR|
|Tour Championship||Tournament Not Held||DNQ||DNQ||DNQ|
|Former ranking tournaments|
|Paul Hunter Classic||Minor-Ranking||A||1R||A||NR||NH|
|Indian Open||A||A||NH||A||SF||LQ||Not Held|
|China Open||A||A||A||A||LQ||1R||Not Held|
|China Championship||Tournament Not Held||NR||LQ||1R||LQ||NH|
|Former non-ranking tournaments|
|Performance Table Legend|
|LQ||lost in the qualifying draw||#R||lost in the early rounds of the tournament
(WR = Wildcard round, RR = Round robin)
|QF||lost in the quarter-finals|
|SF||lost in the semi-finals||F||lost in the final||W||won the tournament|
|DNQ||did not qualify for the tournament||A||did not participate in the tournament||WD||withdrew from the tournament|
|NH / Not Held||means an event was not held.|
|NR / Non-Ranking Event||means an event is/was no longer a ranking event.|
|R / Ranking Event||means an event is/was a ranking event.|
|MR / Minor-Ranking Event||means an event is/was a minor-ranking event.|
- It shows the ranking at the beginning of the season.
- He was an amateur.
- New players on the Main Tour don't have a ranking.
- Players qualified through Q School started the season without ranking points.
- Players qualified One Year Ranking List started the season without ranking points.
Amateur finals: 1 (1 title)
|Outcome||No.||Year||Championship||Opponent in the final||Score|
|Winner||1.||2016||IBSF World Under-21 Championship||Alexander Ursenbacher||6–5|
- "Shanghai Masters 2014: Schedule & results". BBC Sport. 3 September 2014. Retrieved 5 June 2017.
- "World Open 2016: Schedule & results". BBC Sport. 31 July 2016. Retrieved 5 June 2017.
- "2016 International Championship". Cuetracker. 1 November 2016. Retrieved 5 June 2017.
- "Xu Si is 2016 IBSF World Under-21 boys champion". International Billiards and Snooker Federation. 25 August 2016. Retrieved 5 June 2017.
- "Xu Si Wins World U-21 Championship". WPBSA. 27 August 2016. Retrieved 5 June 2017.
- "Xu Si". World Snooker. 11 January 2015. Retrieved 5 June 2017.
- "Ranking History". Snooker.org. Retrieved 6 February 2011.