Abstract: To understand the influence of synthetic fiber and rubber particles on the mechanical properties of wet shotcrete,the mechanical properties of fiber reinforced rubber wet shotcrete were tested in the laboratory. The influences of glass fiber,polypropylene fiber and rubber particles on mechanical properties of wet shotcrete were systematically analyzed. The experimental findings revealed that the strength index of wet shotcrete exhibited an increase in response to an increase in glass fiber content. However,the strength index initially increased and then decreased with an increase in polypropylene fiber content. Among the factors studied,glass fiber content had the greatest influence on compressive strength and flexural strength,followed by rubber particle content,while the impact of polypropylene fiber content was relatively minimal. In terms of tensile strength,glass fiber content remained the most influential,followed by rubber particle content,with polypropylene fiber content having the least impact. Compressive strength was significantly influenced by the content of glass fiber and rubber particles,while tensile and flexural strength were notably influenced by the content of glass fiber and polypropylene fiber. It was observed that the strength index was not solely affected by individual factors but also by the interaction between factors,which had a significant impact on the overall strength index. The results of the multi-objective optimization for the strength index indicated that the optimal ratio of the three materials added to wet shotcrete was as follows:glass fiber content of 0.25%,polypropylene fiber content of 0.21%,and rubber particles content of 3.80%. The inclusion of fibers allowed for load-bearing capacity,while the addition of suitable rubber particles effectively filled the internal pores of the samples,thereby enhancing their mechanical properties.