Abstract: Molecularly imprinted polymer(MIP) was prepared by optimized method using formaldehyde as template molecule,α-methacrylic acid as functional monomer,ethylene glycol dimethacrylate as crosslinking agent in chloroform. The imprinted polymer has the best selective adsorption capacity when the molar ratio of template molecular,functional monomer,crosslinking agent is 1:2:20,the prepolymerization time is 4 h,and the polymerization time is 8 h. When the concentration of formaldehyde solution is 2 mmol/L,the adsorption capacity of MIP reaches 12.40×10^-2 mmol/g. The analysis of squid water sample indicated formaldehyde concentration was 5.92 mg/Kg. At the same time,formaldehyde was not detected when the test sample was diluted 100 times,while after enriched by MIP solid-phase extraction (MIPSE) the concentration of formaldehyde was 5.76 mg/Kg. Formaldehyde MIP has high-efficiency in enriching low concentration formaldehyde for sample preparation,and there is no significant difference in the testing results.