The precision ball is the most key component of ball bearing, which is widely used in many precision mechanical fields. This paper presents a variable-radius V-groove lapping method since this method can make the spin angle vary between 0 deg and 90 deg, and the lapping trajectory can cover the ball's surface. Based on this lapping method, an observation of lapping surface of balls experiment is set up in which blackened balls is brightened effectively only after 10 circulations of lower plate in 2 min. Next, another experiment is also done: A batch of G16 level steel balls has been lapped to G5 level in the machining experiment. All results illustrate that the novel method has properties of high efficiency, high precision, and high consistency, which needs further study and then it is likely to replace the traditional one in the future.