Control method and control device for electronic expansion valve

The invention discloses a control method and a control device for an electronic expansion valve. The method includes the following steps: sucked vapor superheat degree and evaporator superheat degree in a system are calculated, wherein the system is a system comprising the electronic expansion valve; whether the sucked vapor superheat degree is within a preset sucked vapor superheat degree range is detected; if the sucked vapor superheat degree is within the preset sucked vapor superheat degree range, the opening degree increment of the electronic expansion valve is controlled at a first preset opening degree increment according to the evaporator superheat degree. The invention solves the problem in the prior art that a single-parameter-controlled scroll unit system cannot ensure reliability and energy efficiency under any working conditions.