A new hydrolysable crosslinking agent LC with β-quaternary ammonium structure was synthesized by quaternization reaction of dimethylaminoethyl acrylate and 1,4-dibromobutane. By inverse miniemulsion polymerization, a series of cross-linked polyacrylamide (PAM) microspheres with delayed-swelling characteristics were prepared, containing LC alone or LC and N, N-methylene bisacrylamide (Bis). The particle size of the microspheres was 300 nm ~ 500nm, and the distribution was narrow. The delayed-swelling characteristics of crosslinked PAM microspheres can be dissected by light transmittance. The research showed LC showed faster hydrolysis rate than non ionic acrylate. The swelling time (tS) was 2 d as pH=8.9, while tS was increased to 40 d. Its hydrolysis rate was decreased with the decrease of pH, and the weak acid condition can inhibit the hydrolysis of LC. The swelling time can be adjusted by the usages of LC (2 % ~ 5 %)and Bis(0 ~ 0.05 %), the temperature(75 ~ 100 ℃) and pH(5.0 ~ 8.9), and changed from 2 d to 40 d. The new hydrolysable cross-linker LC and the PAM microspheres prepared by LC-Bis compositecross-linkers have application prospects in depth profile control and water plugging.