The invention provides a plastic hot cutting machine, and belongs to the technical field of plastic machining equipment. One end of a hollow same-direction water cooling chrome-plated shaft roller is connected with a shaft roller water input and output pipe, two chrome-plated large-paired-roller shaft roller cylinders are of a hollow structure, a roller cylinder water input and output pipe is connected to each chrome-plated large-paired-roller shaft roller cylinder, cooling paired-roller knives are of a hollow structure, a cooling paired-roller knife water input and output pipe is connected to each cooling paired-roller knife, one pair of cooling paired-roller knives is made of chrome-12 steel pipes with the diameter of 10 cm, and isometric concave and convex grooves are formed in the outer faces of the cooling paired-roller knives. According to the machine, the technical problem that plastic particles are easily affected with damp in the rainy season and cannot be normally used is solved, the problem that plastic is in direct contact with water, and water pollution is caused is solved, original mechanical devices are fully utilized, a large amount of fund waste is avoided, resources are saved, and the fund problem is solved. Meanwhile, products are regular small-cuboid particles, and multiple kinds of plastics exist and are suitable for the plastic hot cutting machine.