The invention discloses a head of a plastic extruder. The head comprises an outer cylinder assembly and a filter core assembly installed in the outer cylinder assembly; the outer cylinder assembly comprises an outer cylinder (3), the filter core assembly comprises a filter tube (4), a discharge outlet of the filter tube (4) is communicated with a discharge outlet of the outer cylinder (3), and a filter screen (5) adheres to the peripheral wall of the filter tube (4). According to the invention, a high temperature plasticized material entering into the outer cylinder assembly is filtered by the filter screen at first so as to remove large impurities and then is filtered by filter pipe again, and therefore, a filtering effect is effectively enhanced.