Constant temperature and humidity testing machine, constant temperature and humidity test chamber, programmable wet heat alternating test chamber, constant temperature machine or constant temperature and humidity chamber, equipment used to test the performance of materials in various environments and test the heat resistance, cold resistance, dry resistance, and moisture resistance of various materials. Suitable for quality testing of electronic, electrical, mobile phone, communication, instrument, vehicle, plastic products, metal, food, chemical, building materials, medical, aerospace and other products.