The invention discloses a method of using waste timber to manufacture finger joint jointed boards. The method of using the waste timber to manufacture the finger joint jointed boards comprises the following steps: S1: arranging the waste timber; S2: polishing processing; S3: sawing into flaky boards; S4: selecting the boards in a classified way and conducting refurbishment processing; S5: combing teeth processing; S6: gluing to form finger strips; S7: piecing into base boards of the finger joint jointed boards after all sides are polished; S8: processing the base boards of the finger joint jointed boards in a cold pressing mode through a board cold press; S9: and conducting edge sawing and sanding processing on the base boards of the finger joint jointed boards which are processed in a cold pressing mode to obtain finished products of the finger joint jointed boards. The method of using the waste timber to manufacture the finger joint jointed boards enables the slightly corroded timber to be reused after the refurbishment processing of the whitening of the slightly corroded timber and gum dipping, so that use rate of the waste timber is improved. In addition, the method of using the waste timber to manufacture the finger joint jointed boards is simple in procedures and can manufacture the finger joint jointed boards which are similar to a solid board only through two-time brush coating and one-time cold pressing, so that energy and consuming cost of auxiliary materials are reduced.