The invention discloses a belt conveyor with an adjustable inclination angle. The belt conveyor comprises a base, a fixing base is arranged on the base through a first bolt, a mounting frame is connected to the outer side of a transmission roller through a second fixing part, one side of a brake device is connected with a speed reducer through a rotating shaft, one side of a coupler is connected with a transmission barrel, a speed sensor is arranged at the position, below a conveying belt, of the surface of the mounting frame, a pressure sensor is arranged at the position, on one side of the speed sensor, of the surface of the mounting frame, a redirection roller is arranged at the inner side, at one side of the belt tensioner, of the mounting frame through a first fixing part, and the position, below the first fixing part, of the outer side of the redirection roller is connected with a hydraulic cylinder through a piston rod. Through the hydraulic cylinder, the piston, the mounting frame, a control box, the pressure sensor, the speed sensor, and a speed reducer structure, the problems that the inclination angle of the belt conveyor cannot be adjusted, and the belt conveyor cannotadjust the speed according to the weight for more efficient conveying are solved.