Axillary crutch is one of the common mobility aids, with extensive usage in the given crowd. Due to the lack of adequate theoretical support, the past design of crutches often leads to occurrence of the secondary damage, such as axillary nerve injury, wrist injury and so on. Thus, it is necessary to carry out biomechanical study on axillary crutches. In this paper, the problems related with biomechanics in axillary crutches were reviewed by inquiring and analyzing the relevant references, and discussed from the aspects of human biomechanics, ergonomics, and industrial design. Also in this paper, through man machine interface research, the mechanical analysis on crutches usage, gait analysis and ergonomics design were made to lay a solid foundation for the design and correct use of axillary crutches so as to provide some reference for the option, adaptation and assessment of axillary crutches, which would have great clinical significance.