The invention provides a measurement method of a cell and UE. The measurement method comprises the following steps that user equipment (UE) receives system information broadcast issued by a base station and acquires a radius of a cell where the UE is located and paging time of the UE according to the system information broadcast; the UE estimates a speed of the UE itself in an idle state; the UE opens a receiver to carry out cell measurement according to the radius, the speed and the paging time and prolongs turn-off time of the receiver. In the above method, the UE estimates the radius of the cell in the idle state according to a cell PRACH type; according to the cell radius and the speed of the UE itself, measurement is optimized; under the condition that UE mobility and paging are ensured, power losses caused by the measurement are reduced and terminal standby time is prolonged.