The printer paper pressing mechanism comprises a printer body and a printing channel arranged in the printer body, a printing area of the printing channel is provided with a printing head, and the printing head is used for printing paper passing through the printing area; the two paper pressing sheets are arranged in the printing area of the printing channel, located on the two sides of the printing head correspondingly and used for pressing the two sides of the paper passing through the printing area, the side edges of the paper are prevented from being folded when the printing head conducts printing, and meanwhile paper feeding and clamping caused by the fact that the head of the paper is rolled up can be prevented. The two paper pressing sheets are arranged in the printing area of the printing channel, when paper passes through the printing area, the two sides of the paper can be pressed below the paper pressing sheets, in this way, when the printing head conducts reciprocating printing, the side edges of the paper cannot be folded, the paper clamping probability is reduced, and the working efficiency of the printer is improved.