A method for switching a monitoring frequency channel number by an access terminal, wherein the method comprises: obtaining (S101, S202), by the access terminal, a first expected frequency channel number according to a first session seed, which is sent to the network side by using a Random Access Terminal, RATI, process, and a first sector parameters message, which is received by searching a network, when an Evolution-Data Optimized session of the access terminal is in a closed state or in an initialization process; determining (SI02, S203) whether the first expected frequency channel number is the same as a frequency channel number of a signal currently received by the access terminal; generating (S103, S205), by the access terminal, a second session seed different from the first session seed when it is determined that the first expected frequency channel number is different from the frequency channel number of a signal currently received by the access terminal, and sending, by using a RATI process, the second session seed to the network side, so that the network side can obtain, according to the second session seed, a sending frequency channel number that is the same as a second expected frequency channel number and used to send data to the access terminal; receiving (S104, S207), by the access terminal, a second sector parameters message by re-searching the network; obtaining (S105, S208), by the access terminal, the second expected frequency channel number according to the second sector parameters message, the second session seed, and a non-coherence parameter; and switching (S106, S210), by the access terminal, a monitoring frequency channel number to the second expected frequency channel number if the second expected frequency channel number is the same as the frequency channel number of a signal currently received by the access terminal, and not switching (S106, S210) said monitoring frequency channel number if the second expected frequency channel number is different from the frequency channel number of a signal currently received by the access terminal. obtaining (S101, S202), by the access terminal, a first expected frequency channel number according to a first session seed, which is sent to the network side by using a Random Access Terminal, RATI, process, and a first sector parameters message, which is received by searching a network, when an Evolution-Data Optimized session of the access terminal is in a closed state or in an initialization process; determining (SI02, S203) whether the first expected frequency channel number is the same as a frequency channel number of a signal currently received by the access terminal; generating (S103, S205), by the access terminal, a second session seed different from the first session seed when it is determined that the first expected frequency channel number is different from the frequency channel number of a signal currently received by the access terminal, and sending, by using a RATI process, the second session seed to the network side, so that the network side can obtain, according to the second session seed, a sending frequency channel number that is the same as a second expected frequency channel number and used to send data to the access terminal; receiving (S104, S207), by the access terminal, a second sector parameters message by re-searching the network; obtaining (S105, S208), by the access terminal, the second expected frequency channel number according to the second sector parameters message, the second session seed, and a non-coherence parameter; and switching (S106, S210), by the access terminal, a monitoring frequency channel number to the second expected frequency channel number if the second expected frequency channel number is the same as the frequency channel number of a signal currently received by the access terminal, and not switching (S106, S210) said monitoring frequency channel number if the second expected frequency channel number is different from the frequency channel number of a signal currently received by the access terminal.