Objective The article takes a cheese snack heavy metal pollution investigation as a demonstration study， and applies the hazard analysis and critical control point （HACCP） system to conduct a traceability analysis of the cheese snack production process， identifying critical control points and critical limits， establishing investigations for critical control points， and thus finding the source of pollution. It also proposes preventive and control measures， providing a basis for similar food safety incidents prevention and disposal.Methods A total of 55 dried cheese samples were randomly selected in Beijing. The contents of arsenic， lead， mercury， chromium， cadmium and nickel in dried cheese were determined by Inductively coupled plasma mass spectrometry（ICP-MS），and using the principles of the HACCP system to analyze sources of hazards.Results The qualified rate of lead and arsenic was 100%. The detection rate of cadmium was 0.0%， which was lower than the detection limit. The detected values of chromium and nickel were higher， with average values of 25.367 and 13.320 mg/kg， respectively. According to the analysis of Nemerow comprehensive pollution index method the comprehensive pollution index of chromium and nickel is much higher than 3.0， and the pollution is classified as severe pollution according to the degree of pollution， and the pollution degree is quite serious. According to the principle of HACCP， the pollution source of chromium and nickel is analyzed as a metal shaft in the production container， which has been used for a long time， leading to aging and serious dissolution of chromium and nickel， and the detection result is normal after replacement.Conclusion By establishing a HACCP system or formulating local food safety standards with local characteristics to regulate the production of enterprises and provide a basis for supervision， according to the characteristics of food production in the region to develop the corresponding risk monitoring plan， or establish a regional risk assessment database， identify and control risks immediately.