The invention provides a method for controlling broken edge when cutting a silicon slice, which comprises that: a rolling-finished silicon rod is adhered to a cutting machine; the rotating speed of the silicon rode, the knife-advancing speed of the cutting machine and the surface temperature of the blade of a cutting knife are regulated and controlled for cutting the silicon rod. The improvements of the method are that: the knife-advancing speed for cutting is controlled at 0.02cm/min to 0.1cm/min; the rotating speed of the silicon rod is controlled at 100turn/min to 500turn/min; the flux of cooling water is controlled at 2L/min to 5L/min; the surface temperature of the blade of the cutting knife is maintained lower than 40 DEG C. The method is applicable to the internal circle cutting and the line cutting in the processing of the silicon slice. By changing the conditions of a cutting technology, the effect for controlling the incidence rate of the broken edge of the silicon slice is realized; thus having the advantages of reasonable design of technological conditions, simple and convenient operation and relatively low production cost.