The acrylate emulsion pressure sensitive adhesives (PSA) with a solid content of up to 62% were synthesized by unseeded semi-continuous emulsion polymerization technology using butyl acrylate (BA), methyl methacrylate (MMA), acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA) as monomers, allyloxy fatty alcohol polyoxyethylene ether ammonium sulfate (SR-10) and alkyl polyoxyethylene ether succinate monoester disodium sulfonate (A-102) as hybrid emulsifiers. The effects of the amount of hard monomer MMA on the properties of the latex PSAs were investigated. Results indicated that when the amount of MMA accounts for 10% of the total monomer, the glass transition temperature (Tg) is -32.6 °C, the initial thermal decomposition temperature is 337 °C, the water contact angle is 108°, the loop tack is 9.53 N/25mm, the 180° peel strength is 10.08 N/25mm, and the shear holding power is more than 72 h; Compared with the high-solid emulsion without MMA, the viscosity of the emulsion decreased from 361 mPa·s to 155 mPa·s, the particle size decreased from 375 nm to 350 nm, and the particle size distribution index increased from 0.144 to 0.214.