Lin was picked for the
Hainan provincial team in 2015. After winning the singles title at the national youth championships in 2020, Lin joined the
Chinese national second team. He represented China at the
2022 ITTF World Youth Championships, winning four gold medals including the U-19 singles title. In 2023, Lin Shidong won the WTT Contender series event in Amman. He paired with
Kuai Man in the mixed doubles event at the
2023 World Championships, winning bronze in his first appearance at the Championships. After claiming the men's singles title at the
All China Table Tennis Championships, After the
2024 Summer Olympics, Lin Shidong won the men's singles titles at the WTT Contender Almaty and WTT Champions Macao in September. He continued his success in October by defeating
Ma Long in the final to win the WTT China Smash. His winning streak ended in the men's singles final at the
Asian Championships, where he was defeated by
Tomokazu Harimoto. Lin subsequently claimed two additional singles titles at the WTT Contender Muscat and WTT Champions Frankfurt. In 2025, Lin won the WTT Singapore Smash title by defeating
Liang Jingkun in the final, and subsequently reached the No. 1 position in the ITTF world rankings in February. He competed at the
ITTF Men's World Cup as the top-ranked player, advancing to the final where he finished as runner-up to
Hugo Calderano. At the
2025 World Championships, Lin was the only male Chinese player to compete in three events and entered as the top seed in both singles and mixed doubles (with
Kuai Man). He was eliminated in the quarterfinals of all three events and did not medal. In summer 2025, Lin participated in the WTT United States Smash, he lost in the semi-final against
Tomokazu Harimoto 3-4. Then Lin joined WTT Champions Yokohama and had a surprising lost to
Dang Qiu in the round of 16. The next tournament is the Europa Smash in Sweden, where Lin reached the final after successively taking revenge against Dang Qiu in the quarterfinal 4-0 then beating French
Simon Gauzy in a thrilling game 4-3. In the final, Lin lost 3-4 to
Truls Moregard. Before the last grand smash, Lin went to do The WTT champions in Macao but lost 3-4 in the quarterfinal against Anders Lind. Meanwhile, his compatriot Wang Chuqin won the title, allowing himself to get 1000 ranking points and surpass Lin to become the world no.1 again. ==Singles titles==