The utility model discloses an improved steam trap, which comprises a pipe body. The pipeline of the pipe body is in a waisting shape with two large ends and a small intermediate part. One end of the pipeline is a steam inlet pipeline and the other end of the pipeline is a steam outlet pipeline. The intermediate part of the pipeline is equipped with a through hole and the diameter of the through hole is small. A filter screen is arranged inside the steam inlet pipeline. By adopting the improved steam trap, the detention time of steam in the heat exchanger of a shaping machine is prolonged. The heat of the steam can be fully utilized so as to improve the steam utilization efficiency. The improved steam trap also has the advantages of simple structure, low cost and convenient installation and maintenance.