Bottom ash, as a product of municipal solid waste incineration, similiar to sand soil, can be used as filling material in subgrade. In order to explore the shear strength indexes of the bottom ash, we mixed the bottom ash with clay of different contents and carried out indoor large direct shear tests under two different degrees of compaction. Through the tests, we obtained the values of cohesion and internal friction angle of eight kinds of mixed soils. Results show that 1) compacted bottom ash has good shear resistant ability, and with the increasing of bottom ash content, shear strength and internal friction angle increased, while cohesion decreased; 2) with the increasing of compactness, shear resistant ability increased, cohesion obviously increased, but internal friction angle decreased a little.