A time deviation determining method, wherein the method is used to determine a clock time deviation between a terminal and a base station in a wireless network, the method comprises: determining (S501) an uplink timing advance TA between the terminal and the base station, and determining a one-way transmission delay Q1 based on the uplink timing advance TA and a sampling time of a network in which the terminal is located; receiving (S504) a first packet, wherein the first packet comprises a base-station clock time T1 of a first system frame, and the first system frame is any system frame existing after downlink synchronization between the base station and the terminal is completed, wherein the base-station clock time T1 corresponds to a base-station clock time of sending the first system frame at the base station; determining (S505) a terminal clock time T2 of a second system frame, wherein the second system frame is any system frame following the first system frame, the terminal clock time T2 corresponds to a terminal clock time of receiving the second system frame at the terminal; characterised by determining (S506) a quantity of frames spaced between the first system frame and the second system frame, and obtaining an inter-frame time difference Q2 based on the quantity of spaced frames, wherein the inter-frame time difference Q2 is a product of the quantity of spaced frames and duration of one system frame; and determining the time deviation between the terminal and the base station, wherein the time deviation is duration obtained after the one-way transmission delay Q1 and the inter-frame time difference Q2 are deducted from a time interval between T1 and T2. determining (S501) an uplink timing advance TA between the terminal and the base station, and determining a one-way transmission delay Q1 based on the uplink timing advance TA and a sampling time of a network in which the terminal is located; receiving (S504) a first packet, wherein the first packet comprises a base-station clock time T1 of a first system frame, and the first system frame is any system frame existing after downlink synchronization between the base station and the terminal is completed, wherein the base-station clock time T1 corresponds to a base-station clock time of sending the first system frame at the base station; determining (S505) a terminal clock time T2 of a second system frame, wherein the second system frame is any system frame following the first system frame, the terminal clock time T2 corresponds to a terminal clock time of receiving the second system frame at the terminal; characterised by determining (S506) a quantity of frames spaced between the first system frame and the second system frame, and obtaining an inter-frame time difference Q2 based on the quantity of spaced frames, wherein the inter-frame time difference Q2 is a product of the quantity of spaced frames and duration of one system frame; and determining the time deviation between the terminal and the base station, wherein the time deviation is duration obtained after the one-way transmission delay Q1 and the inter-frame time difference Q2 are deducted from a time interval between T1 and T2. <EOS>