The invention relates to the technical field of grouting engineering, in particular to a slurry emitting control method for separation layer grouting. The method includes the following steps that S11,a tracing test is performed, and the putting time t0 of a tracer at a grouting opening, the starting time t1 when the tracer is gathered at a slurry emitting opening, the peak time t3 and the disappearing time t2 are recorded; S12, the hydraulic communication time of a hydraulic breakover point is acquired, and the average flow velocity of slurry flow is calculated; S13, position coordinates of the hydraulic breakover point are calculated; and S14, the hydraulic breakover point is blocked. According to the method, when the slurry emitting problems when grouting is performed and not performedin a separation layer zone are solved, the slurry emitting position is generalized into one point, the slurry diffusion path is generalized into a columnar channel, the coordinate position of a slurryrun-out point can be obtained through calculation, thus the grouting position is determined, the grouting accuracy is increased, the slurry waste and the loss caused by slurry emitting are reduced, and the slurry emitting control effect is guaranteed.