A method of forming a layering structure of plastic flooring comprising steps of: A. forming a substrate by using an extruder so as to one-piece extrusion form the substrate including at least two sheets, wherein the at least two sheets are a first sheet and a second sheet which stack together; B. delivering a printing layer , wherein the printing layer has patterns printed thereon and is delivered to a roller unit by using a first rolling mechanism and a first pressing mechanism ; C. conveying a abrasion resistant layer , wherein the abrasion resistant layer conveyed to the roller unit by way of a second rolling mechanism and a second pressing mechanism of a rolling conveyor ; D. roll pressing the substrate , the printing layer , and the abrasion resistant layer together by way of the roller unit so as to form a plastic flooring , wherein in step A, the substrate includes three sheets which are one-piece extrusion formed by using an extruder having a first material feeder , a second material feeder and a third material feeder , wherein a material distributor is configured to distribute a material into the first material feeder , the second material feeder and the third material feeder so that three sheets forms the substrate ; and steps B, C and D are carried out using a roller unit that includes a first roller , a second roller , a third roller , two fourth rollers , and a support frame , wherein the first roller is fixed on an end of the support frame , the second roller is located on the first roller , the third roller is disposed beside the first roller and the second roller , and the two fourth rollers are secured beside the third roller opposite to the first roller and the second roller , wherein the step D includes a first sub-step D1 in which the substrate is guided between the first roller and the second roller and is guided to the third roller via a first guide roller ; the step D includes a second sub-step D2 in which the printing layer is guided to the third roller via a guide roller and a first press roller , and the abrasion resistant layer is guided to the third roller through a third guide roller and a second press roller ; the step D includes a third sub-step D3 in which the printing layer is stacked on the substrate , and the abrasion resistant layer is stacked on the printing layer 12 by using the third roller , then the substrate , the printing layer , and the abrasion resistant layer are guided to the two fourth rollers via a fourth guide roller ; the step D includes a fourth sub-step D4 in which the substrate , the printing layer , and the abrasion resistant layer are rolled and pressed together by the two fourth rollers of the roller unit ; and the step D includes a fifth sub-step D5 in which the plastic flooring is removed from the two fourth rollers and is cut based on required sizes. A. forming a substrate by using an extruder so as to one-piece extrusion form the substrate including at least two sheets, wherein the at least two sheets are a first sheet and a second sheet which stack together; B. delivering a printing layer , wherein the printing layer has patterns printed thereon and is delivered to a roller unit by using a first rolling mechanism and a first pressing mechanism ; C. conveying a abrasion resistant layer , wherein the abrasion resistant layer conveyed to the roller unit by way of a second rolling mechanism and a second pressing mechanism of a rolling conveyor ; D. roll pressing the substrate , the printing layer , and the abrasion resistant layer together by way of the roller unit so as to form a plastic flooring , <EOS>