Disclosed is a method and a system for cutting fuel for a hybrid vehicle. More specifically, a control unit in the vehicle is configured to determine margin torque according to each driving mode, determine whether a current vehicle driving condition is a coasting driving condition, compare a engine torque and a sum of friction torque and the margin torque to determine whether the engine torque is greater than the sum of the friction torque and the margin torque and cut fuel injection to the engine when the engine torque is equal to or less than the sum of the friction torque and the margin torque.