The invention discloses a method for processing a short message service by a packet switched domain user, so that the user can autonomously select whether to carry out CS (Customer Satisfaction) Fallback. When the short message service is carried out through user equipment located in a packet switched domain and user equipment located in a circuit domain, the user equipment in the packet switched domain confirms not to fall back to the circuit domain; and the short message service is carried out by the user equipment located in the packet switched domain in a network side of the packet switched domain in a signaling manner. When the method is adopted, the user equipment can fall back the CS autonomously, and the willing of the user to receive a call is represented. UE (User Equipment) can avoid an unnecessary fallback for a nuisance call which may come from a CS domain.