The invention discloses a process for producing a Czochralski silicon single crystal, which comprises the following steps of: 1, preparing a silicon raw material and a doping agent; 2, charging; 3, vacuumizing; 4, melting; 5, extracting slag, namely 501, performing cooling crystallization, 502, gradually heating, and keeping the crystallization process continuously performed until insoluble substances floating on the surface of a silicon melt are completely condensed by the crystal, and 503, taking the crystal out, and removing the slag; and 6, performing subsequent treatment, namely finishing crystal leading, shoulder expanding, shoulder rotating, diameter equalizing, ending and blowing down processes in turn by using a single crystal furnace according to the conventional treatment process of a Czochralski method to obtain the finished silicon single crystal formed by pulling. The process is reasonable in design, simple in steps, convenient to implement, easy to master and good in using effect, can effectively ensure the quality of the produced silicon single crystal, and can solve the practical problems that slag removing time is difficult to master, the slag extracting effect is poor, the produced silicon single crystal has low purity, and the like.