Determination method of Pb,As,Cr,Cd,Cu,Zn,Fe and Mn in biscuit by ICP-MS was researched.The sample was digested by the full automatic microwave, the digestion solution was determined by ICP-MS with Bi,Ge,Sc and In as internal standard, the determination results were validated with the national standard method. The accuracy and reliability of the method were verified by the recovery and analysis of the national standard substance wheat (GBW10052). It showed that all of the linearly dependent coefficients of the curves were more than 0.999, the detection limits varied from 0.002 mg/kg to 0.500 mg/kg, the relative standard deviations were lower than 6.55%, the relative deviations of two methods between 3.73%～8.40%, the recoveries were from 88.0% to 106% ,the results of determination in the national standard substance of GBW10052 were all within the ranges of standard values. The test results are satisfied.