Due to the advantages of simple structure, easy alignment, high spectral versatility, good robustness and low cost, optical multi-pass cell is one of the most effective means to increase the optical path length and can significantly improve the detection sensitivity of absorption spectroscopy. The basic principles of different types of optical multi-pass cells are summarized firstly. Then a series of optical multi-pass cells developed by Prof. Weijun Zhang's group of Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences by using ray tracing, including an astigmatic mirror cell with 200 m optical path length, a Herriott cell with 59.7 m optical path length, a dense spot pattern spherical mirror cell with an optical path longer than 200 m and a Chernin cell with portable stabilization adjustment mechanism, are introduced in detail, especially their design methods and applications inlaser absorption spectroscopy.