A method for forming stereoscopic patterns of plastic floor boards, comprising the steps of: Step A: taking a base board, which has a blank or plain outer surface; Step B: digital printing: positioning the base board on a digital printing unit, and using the digital printing unit to print the pigment on the outer surface of the base board according to the preset pattern, thereby forming a pattern layer, wherein the pattern of the pattern layer corresponds to or does not correspond to the stereoscopic pattern; Step C: forming a protection layer: using a first forming unit to form a protection layer on the pattern layer with a transparent melt plastic raw material; Step D: forming a stereoscopic pattern: using a second forming unit to form a stereoscopic pattern having a concave-convex structure on the protection layer, thus forming the plastic floor board with a stereoscopic pattern; wherein the first forming unit comprises a second machine body, a second conveying platform arranged on the second machine body, and a coating mechanism correspondingly arranged above the second conveying platform, wherein the second conveying platform further comprises two conveying wheels, a plurality of rolling wheels and a conveying belt, wherein the coating mechanism comprises a main roll and an auxiliary roll, and a receiving portion is arranged between the two rolls for receiving the melt plastic raw material, wherein the coating mechanism is controlled by the electrical control system, wherein when the base board is conveyed to a particular position, the melt plastic raw material in the receiving portion is coated on the pattern layer along the rotation of the main roll, wherein through the auxiliary roll and the main roll that rotate in opposite directions, the coating of the melt plastic raw material becomes more uniform; a third conveying platform arranged on the second machine body and a shower-coating mechanism correspondingly arranged above the third conveying platform, wherein the third conveying platform comprises a plurality of conveying wheels capable of propelling the conveying belt to rotate, wherein the lower end of the shower-coating mechanism is provided with a discharging port whose interior allows the melt plastic raw material to flow therein, wherein the melt plastic raw material is vertically discharged from the discharging port in a shower manner, wherein when the base board is conveyed through the lower portion of the shower-coating mechanism, the melt plastic raw material is coated on the pattern layer. Step A: taking a base board, which has a blank or plain outer surface; Step B: digital printing: positioning the base board on a digital printing unit, and using the digital printing unit to print the pigment on the outer surface of the base board according to the preset pattern, thereby forming a pattern layer, wherein the pattern of the pattern layer corresponds to or does not correspond to the stereoscopic pattern; Step C: forming a protection layer: using a first forming unit to form a protection layer on the pattern layer with a transparent melt plastic raw material; Step D: forming a stereoscopic pattern: using a second forming unit to form a stereoscopic pattern having a concave-convex structure on the protection layer, thus forming the plastic floor board with a stereoscopic pattern; wherein the first forming unit comprises a second machine body, a second conveying platform arranged on the second machine body, and a coating mechanism correspondingly arranged above the second conveying platform, wherein the second conveying platform further comprises two conveying wheels, a plurality of rolling wheels and a conveying belt, wherein the coating mechanism comprises a main roll and an auxiliary roll, and a receiving portion is arranged between the two rolls for receiving the melt plastic raw material, wherein the coating mechanism is controlled by the electrical control system, wherein when the base board is conveyed to a particular position, the melt plastic raw material in the receiving portion is coated on the pattern layer along the rotation of the main roll, wherein through the auxiliary roll and the main roll that rotate in opposite directions, the coating of the melt plastic raw material becomes more uniform; a third conveying platform arranged on the second machine body and a shower-coating mechanism correspondingly arranged above the third conveying platform, wherein the third conveying platform comprises a plurality of conveying wheels capable of propelling the conveying belt to rotate, wherein the lower end of the shower-coating mechanism is provided with a discharging port whose interior allows the melt plastic raw material to flow therein, wherein the melt plastic raw material is vertically discharged from the discharging port in a shower manner, wherein when the base board is conveyed through the lower portion of the shower-coating mechanism, the melt plastic raw material is coated on the pattern layer.