According to the empirical electron theory (EET) of solids and molecules, the valence electron structures of (Mo1-x,Wx)Si2 solid solutions were analyzed using the average atom model, and they were compared with those of MoSi2 and WSi2 matrix. Results show that with x value increasing, the bond energy of the main bond branch, the covalence electron number on the strongest bond and the percentage of total covalence electron number of (Mo1-x,Wx)Si2 solid solutions all increased gradually, indicating the increase of melting point, hardness and strength of (Mo1-x,Wx)Si2 solid solutions.