Probability analysis about basic function of finite element analysis software ANSYS was introduced. For the study of structural reliability of steel awning, typical steel structure was established by ANSYS software. Probability analysis module of ANSYS software was used to analysis steel awning reliability, the awning structure load and elastic modulus and various design parameters were chosen as random input variables, APDL command flow file was obtained and analysed which by means of interactive interface operation, and then the maximum stress and maximum deformation was gotten that of the dangerous parts reliability probability, it is concluded sensitivity relationship of design element and target variable, can be for reference for the structure optimization design, improve design efficiency.