The utility model discloses a washstand drain pipe fitting, which comprises a transverse water pipe and a longitudinal water pipe. A lever-type deodorizing device is arranged between the transverse water pipe and the longitudinal water pipe; the lever-type deodorizing device adopts a blocking blade identical with a pipeline orifice to block the pipeline orifice so as to function in deodorizing effectively for a long period of time; the transverse water pipe includes a front transverse expansion pipe and a rear transverse expansion pipe; the rear end of the front transverse expansion pipe is inserted into the rear transverse expansion pipe; and the front transverse expansion pipe is capable of moving in the rear transverse expansion pipe. Accordingly, the horizontal length of the pipe fitting can be adjusted according to site requirements, installation is more convenient, and materials are saved. Furthermore, the longitudinal water pipe is a universal corrugated pipe, when in installation and utilization, the transverse water pipe is tightly attached to the bottom of a washstand, the universal corrugated pipe is installed in an attached manner along a wall, and larger space for storing articles can be reserved on the lower portion of the washstand to facilitate daily life of people.