Smooth temperature control method for environmental test box with electronic expansion valve

The invention discloses a temperature smooth control method for an environmental test box with an electronic expansion valve. Whether the opening degree of the electronic expansion valve needs to be adjusted or not can be automatically judged by judging whether the opening degree output timer of the electronic expansion valve is larger than or equal to the target adjusting period of the opening degree output quantity or not. When the opening degree of the electronic expansion valve is automatically judged to need to be adjusted, the opening degree of the electronic expansion valve is not directly switched to the set target opening degree, the target opening degree subprogram of the electronic expansion valve is called, and the opening degree output quantity of the controller is adjusted according to the target opening degree subprogram, so that the opening degree of the electronic expansion valve is adjusted. Compared with the prior art, whether the opening degree of the electronic expansion valve needs to be