The possibility of increasing recycling volumes of drilling waste using as a filler for producing polymer composites is considered. As a result of the research, modification of recycled high-density polyethylene with waste mud in the form of fine filler particles is carried out.Recycled high-density polyethylene polymer composites, filled with drilling waste with a content up to 30 % are obtained. As a result of the study, regularities of changes in impact strength, ultimate bending and water absorption, depending on the waste mud solids (WMS) content in the recycled polymer are found.It is shown that the introduction of WMS in the form of fine filler particles in recycled high-density polyethylene significantly increases their strength characteristics without a substantial deterioration in water absorption (up to 2.9 % when filled with waste up to 30 %).It is found that the optimum content of drilling waste in recycled high-density polyethylene polymer composites is 20 wt %. At the same time, the maximum values of impact strength and ultimate bending are achieved for the composite with bentonite clay WMS up to 63.3 kJ/m2 and 200.1 MPa, and for the composite with salt WMS up to 38.1 kJ/m2 and 207.4 MPa, respectively. The resulting polymer composites outperform the known similar polymers with the use of such fillers as talc and kaolin. This allows recommending joint recycling of drilling and polymer waste