The invention provides a field regulating method for improving facility salinity soil. The method comprises the steps of applying soil structure conditioners and soil water-retaining agents on the surface of soil in sequence, mulching the soil with straw pieces to form a straw mulching layer, and spraying EM active calcium liquid onto the straw mulching layer finally. According to the method, regulation is conducted with the straw, the soil structure conditioners, the soil water-retaining agents, quick lime and effective microorganisms as main raw materials, facility cultivation salinity soil salinity is effectively reduced, and the content of organic matter, available nitrogen, phosphorus and potassium in surface soil is increased.