Bruton tyrosine kinase (BTK) is a key mediator of B-cell receptor signalling cascade and an effective target for treating mantle cell lymphoma (MCL). BTK inhibitors play a critical role in the treatment of MCL. Here we introduced the mechanism of action of BTKI in the treatment of MCL. Though generally well prescribed, Ibrutinib, as the first BTKI, still has limitations of toxicity and resistance. New BTK inhibitors, such as zanubrutinib, acalabrutinib and orelabrutinib, are designed to improve on the safety and efficacy as first-generation BTK inhibitors. Comparing the similarities and differences of the two generations of BTKI in structure and function provides a basis for better clinical application of BTKI. On November 15, 2019, FDA approved zanubrutinib for marketing for patients with adult mantle cell lymphoma. Compared with Ibrutinib, zanubrutinib was found with higher target selectivity, longer-lasting inhibition, fewer adverse reactions, and better patient benefit. Zanubrutinib provides a viable treatment option for patients with r/r MCL. At the same time, it is also actively carrying out clinical researches on the treatment of other B-cell lymphomas. It is a very promising targeted drug.