A shell-and-tube heat exchanger capable of conveniently cleaning a shell pass is composed of an end socket, an end socket flange, a tube sheet, a heat exchange tube, a shell, a spraying pipe spacer, a baffle plate, pollution discharge nipples, a support and the like. The shell-and-tube heat exchanger capable of conveniently cleaning the shell pass is characterized in that a plurality of pollution discharge nipples are designed at the bottom of the shell, and a spaced rod in an existing technology is replaced by the spraying pipe spacer. When a cleaning operation is needed, blind plates of the pollution discharge nipples are dismounted, pollution discharge water pipes are connected, the end socket is dismounted, an end cap of the spraying pipe spacer is screwed off, a high-pressure water pipe is connected, and cleaning can be carried out by filling high-pressure water. Sewage after being cleaned is collected into a high-pressure cleaning machine through the pollution discharge water pipes, the sewage is recycled after filtration treatment to reduce or avoid the pollution on surroundings. According to the shell-and-tube heat exchanger capable of conveniently cleaning the shell pass, the problem that a shell pass of a common shell-and-tube heat exchanger is cleaned difficultly is solved, the shell-and-tube heat exchanger capable of conveniently cleaning the shell pass has positive significance that use efficiency of the shell-and-tube heat exchanger is improved, washing and maintaining cost are reduced, and the service life is prolonged. According to the technical scheme, the shell-and-tube heat exchanger capable of conveniently cleaning the shell pass is suitable for fixing various shell-and-tube heat exchangers which are of a shell-and-tube type, a floating-head type, a U-shaped-tube type and the like.