A series of random binary poly(ethylene glycol) and fluoropolymer brushes (POEGMA-PNCA-F₁₅) are grafted onto substrates via surface-initiated polymerizations (atomic transfer radical polymerization and ring opening metathesis polymerization, respectively) from polydopamine based mix-catecholic initiators. The chemical composition, surface morphology, swellability, and wettability of the as-prepared surfaces are characterized by X-ray photoelectron spectra (XPS), atomic force microscopy (AFM), and static water contact angle measurements, respectively. The antifouling properties are evaluated by settlement of spores and diatoms, the results indicate that the as-prepared amphiphilic surfaces with random hydrophilic and hydrophobic polymer brushes can mitigate biofouling, and the ratio of the hydrophilic and hydrophobic polymer brushes is a key determinant factor in antifouling effect, the optimal ratio (1:1 initiator) of bipolymer brushes on surfaces exhibits good antiadhesion performance against both Chlorella spores and Navicula diatoms.