Abstract: In order to realize the resource utilization of bloom algae and penicillin residue and further improve the mechanical properties of algae powder-penicillin residue/low density polyethylene (LDPE) composites, the mixture of penicillin residue with algae powder from Chao Lake and LDPE were used as the raw materials. The experimental scheme was designed by the response surface method, and the effects of the addition of polyethylene wax (PE-wax) and white oil, maleic anhydride grafted polyethylene (PE-g-MAH) and triethanolamine on the mechanical properties of the algae powder-penicillin residue/LDPE composites were studied. When the mass ratios of mixture of penicillin residue with algae powder and LDPE are 15.00% and 85.00%, the results of variance analysis of response surface regression equation show that the interaction between PE-g-MAH and triethanolamine is significant, but the interaction between lubricant and PE-g-MAH, lubricant and triethanolamine is not significant. The optimum process parameters predicted by the response surface regression model are as follows: when the mass ratios of lubricant, PE-g-MAH and triethanolamine are 3.08%, 4.33% and 4.23%, the tensile strength, flexural strength and flexural modulus of the algae powder-penicillin residue/LDPE composites are 12.30 MPa, 9.03 MPa and 220.00 MPa, respectively, which are increased by 10.81%, 29.74% and 34.97%, compared with the algae powder-penicillin residue/LDPE composites without additives.