In this study, trace elements in the flue gas at the inlet/outlet of SCR, ESP and WFGD at a 600MW coal-fired power plant were sampled by the USEPA Method 29 simultaneous. The emission of 12 trace elements (Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Ba, Pb) was studied. The results showed that the mass balance rates of trace elements of the entire power plant system, boiler, SCR, ESP, and WFGD were within an acceptable range, which indicates experimental results are accurate and reliable. The 12 trace elements were mainly distributed in the ESP fly ash with relative distribution rates of 69.97%~98.79%. The relative enrichment indexed of trace elements in the bottom slag were between 0.04 and 0.51 and that in the ESP fly ash were between 0.3 and 1.23. As, Cd and Pb in ESP fly ash and Mn, Co and Ni in WFGD wastewater may pollute soil and groundwater, which need to give enough attention. The emission concentration of 12 trace elements into the atmosphere was 0.02~12.57μg/m³ with the emission factor of 0.01~2.13g/10¹²J. The emission concentration of Ni, As, Cd and Pb reached 2.04, 0.13, 0.02 and 3.35μg/m³, respectively, which far exceed the emission limits of the European Union air quality standards and should be restricted.