GB/T 20969.5-2008 "Special environmental conditions plateau machinery, Part 5: Guidelines for testing plateau natural environment Engineering machinery", focusing on engineering machinery in plateau environment. The standard specifies the purpose and scope of application of the test, and stipulates the test items, procedures, methods and results evaluation criteria of Engineering machinery for special environments such as low oxygen, low pressure and large temperature difference on plateau. Provide technical guidelines for testing the performance, adaptability and Reliability of Engineering machinery under plateau working conditions.