Abstract: For solving the problems of poor supporting effect，high repair rate of the traditional dry shotcrete-rockbolt-mesh support in Jinchuan nickel mine，which is fractured and under high geo-pressure，the wet shotcrete technology is adopted to make the situation better.The effects of water-cement ratio，cement，water reducer and sand-coarse aggregate ratio（fine mung bean stone mass ratio）on workability and mechanical properties of wet shotcrete are studied in mix proportion experiment by using orthogonal design.The results show the effect sequence as following：water-cement ratio> cement dosage > sand-coarse aggregate ratio> water reducer dosage.And，water-cement ratio greater than 0.44，cement dosage greater than 430 kg/m3，a 2~4 sand-coarse aggregate ratio are necessary to acquire a slurry with a slump greater than 150 mm.Cement dosage is the biggest influence on the mechanical properties of wet shotcrete，followed by water-cement ratio and water reducer in sequence.The relationship curve between sand-coarse aggregate ratio and strength of wet shotcrete is a convex curve.The economical efficiency of wet shotcrete with different cement dosages is researched by introducing the concept of the coefficient of strength per unit cost V.Finally，the optimum mix proportion is determined.The application of the wet shotcrete achieves good effect and higher comprehensive economic benefit.

Key words: High-stress fractured nickel mine, Wet shotcrete, Mix optimization, Economical efficiency