Monosilane can be used to manufacture various high purity crystalline silicon, non- crystalline silicon, silicon nitride, silicon oxides and metal silicides as a Si source gas. A method of producing monosiliane was provided with magnesium silicide and ammonium chloride as raw materials, anhydrous ammonia as solvent, autoclave as pressure batch reactor. By the research of reaction ratio, water in liquid ammonia, concentration of ammonium chloride solution, reaction time and reaction temperature, the obtained optimal conditions were that ratio of ammonium chloride to magnesium silicide was 8∶1, water in liquid ammonia was below 10-5, the solution of liquid ammonium including ammonium chloride was 20%，reaction time was 3 h, reaction temperature was -20 ℃. The yield of monosiliane was more than 95%.