Printing method and 3d printer

A 3D printer, comprising:

• a forming module, wherein the forming module defines a receiving cavity, and comprises a light-transmissive assembly arranged on one side of the receiving cavity and a forming platform arranged opposite to the light-transmissive assembly, the receiving cavity receives printing material and comprises a forming cavity located between the forming platform and the light-transmissive assembly, and the forming platform is movable toward or away from the light-transmissive assembly;
• a storage device;
• and
• at least one processor;
• wherein the storage device stores one or more programs that, when executed by the at least one processor, cause the at least one processor to:
• control an air pump to inject gas into the receiving cavity based on an air pressure control algorithm until an air pressure in the receiving cavity is higher than an ambient air pressure;
• obtain a pressure difference based on the air pressure in the receiving cavity and the ambient air pressure;
• determine a driving force for moving the forming platform away from the light-transmissive assembly based on the pressure difference;
• and
• control the forming platform to move away from the light-transmissive assembly based on the driving force.