In the ketone oxamidinating reaction system with water mutually soluble low-carbon alcohol of 30-50 wt% concentration and excessive ammonia water content, the material including titania-silica molecular sieve is deposited at 60-85 deg.c in deposition rate of 0.5-3 cm/min for at least 10 min. The present invention can realize the continuous separation of titania-silica molecular sieve from reaction liquid and is suitable for cyclohexanone oxamidinating reaction system with titania-silica molecular sieve catalyst of 0.1-0.3 micron size. |