In order to study the influences of the dip angle and moisture content of weak interlayer on the mechanical properties and failure characteristics of composite rock mass containing weak interlayer, the composite rock mass samples containing 5 kinds of weak intercalations with five different dip angles and three kinds of moisture content are made and the indoor uniaxial tests are carried out through indoor sample preparation. The results show that with the increase of the dip angle, the peak strength and deformation modulus of the weak intercalation decrease and the peak strain increases; In the experiment, regardless of the inclination angle of the weak interlayer, both sides of the weak interlayer are the first to fail. When the inclination angle θ of the weak interlayer is 15°, 20°, and 25°, the weak interlayer not only develops bilateral failures, but also develops through oblique cracks starting from the top surface on the left side and ending at the bottom surface on the right side. The corresponding failure mode has also been inferred through theoretical research. When the inclination angle of the weak interlayer remains unchanged, as the water content of the weak interlayer increases, the peak strength and deformation modulus of the weak interlayer first increase and then decrease, and the strain at the peak strength point first decreases and then increases, and the bearing capacity of the samples with 8% moisture content is the strongest, and at this time, the peak strength and deformation modulus of the weak interlayer are the highest.