“…A large number of works on this subject for smooth differential systems have emerged, such as in [2,5,7,14,17,18] and references therein. In recent years, much attention has been paid to this problem for piecewise smooth systems [1,4,6,8,10,11,12,22,23]. It is well known that there are two main methods, Melnikov function method and the averaging method, which are used to investigate the number of periodic solutions for smooth or piecewise smooth planar differential equations, see [2,5,6,7,10,11,12,13,14,15,16,17,18,21,22,23] and references therein.We denote by H p (n) the number of limit cycles of piecewise smooth polynomial differential systems of degree n. In [8], Huan and Yang provided an example and numerical simulations to illustrate that H p (1) ≥ 3.…”