Study on waste water containing chromium of continuous foam separation. In continuous foam separation, surface-active agent was inputted into the system at adding mode. Under certain height of liquid level, the influence of the height of chang-in, pH value of the wasterwater, the feeding speed of SDS, the charging capacity of Fe(NO 3 ) 3 , gas flux and charge-in flux on foam flotation effect was investigated and the optimal parameters was obtained. The concentration of chromium ion was about 0.3 mg.L -1 , COD was smaller than 100 mg.L -1 . PH value was close to neutrality, which reach the Second Wastewater Discharge Standard of Country.