The invention relates to a method for preparing 3D printing pre-coated sand from recycled glass and pre-coated sand prepared from the method. The method comprises the following steps of: taking recycled glass, ceramsite and iron sand as crude sand; performing high-temperature firing, and cold water quenching pretreatment, adding polyhydroxyl resin, a dispersing agent, a coupling agent and an initiator to modify crude sand, adding the modified crude sand into a sand mixer, controlling the rotation speed of the mixer to be 100-200 rpm, heating for 1-2 hours at a temperature of 100-150 DEG C, uniformly spraying the dispersing agent, a binder and a curing agent to the surface of the modified crude sand, adding auxiliary materials, stopping stirring after reaction is completed, taking out the auxiliary materials after cooling the materials, crushing, screening and packaging, thereby obtaining 3D printing pre-coating sand. The pre-coated sand prepared from the method has tensile strength of7.5-8.5 MPa at the room temperature, has bending strength of 4-5 MPa, has greatly improved strength, and can be used to replace conventional pre-coated sand to be used in the 3D printing industry; andmeanwhile, the pre-coated sand further can be suitable for manufacturing a 3D printed product with higher requirements on strength.