Abstract: In view of the difficulty of sufficient solid solution of CuNiCoSi quaternary high strength and high conductivity alloy, the grain structure and precipitate morphologies of the CuNiCoSi alloy at different rolling states were characterized firstly, then the cold-rolled CuNiCoSi alloy strips were solution treated at different temperatures and time, and the effects of deformation and heat treatment on the microstructure, precipitates and mechanical properties of the alloy were studied. The results show that the grain structure of the CuNiCoSi alloy is refined with the increase of total rolling strain, while the size of the (Ni, Co)_xSi precipitates increases in a certain extent. The solid solution rate and final solution degree of the cold-rolled CuNiCoSi alloy mainly depend on the solid solution temperature, and prolonging the solid solution time can not increase the solid solution degree. Recrystallization occurs after solution for only a short time, and the deformation texture disappears. Prolonging the solid solution time will result in grain coarsening and the decrease in the strength of the alloy. The solid solution degree does not increase linearly with increasing solid solution temperature, and there is a temperature range in which the precipitates decompose rapidly.