The invention relates to an injection molding method for an environment-friendly plastic box. Plastic box machining and manufacturing equipment is used and comprises a workbench and a placing table rotatably arranged on the outer wall of the workbench, a feeding device is arranged at the top of the workbench, a cooling device is arranged above the placing table, a dismounting device is arranged above the placing table, and a cleaning device is arranged above the placing table. According to the injection molding method for the environment-friendly plastic box provided by the invention, through cooperation of a current-conducting plate, an air pump and a battery, when the battery makes contact with the current-conducting plate, the air pump is powered on, airflow generated in the air pump is jetted to a feed hopper through an air blowing pipe, and therefore waste remaining on the inner wall of a mold box after demolding can be automatically cleaned, the waste in the mold box is prevented from being accumulated, the production quality of the plastic box is influenced, the cleaning time is saved, the working efficiency is improved, and the manpower is saved.