A high precision and high efficiency trigger control scheme for the touch probe in a high-sensitive nano Coordinate Measurement Machine(nano-CMM) is developed,and a self-developed 4-DVD touch probe is used in the proposed scheme. When the probe touches the workepiece, the tiny deformation of the probing system will generate a high-sensitive trigger signal. By integrating different driving modes of an ultrasonic motor, the trigger control scheme realizes the combination of high-speed approaching and low-speed touching.Furthermore, a double-trigger method is used in the touching process. The first trigger is to determine the rough range of the trigger point and the second trigger is to record the trigger signal in detail by a very low speed and to work out the turning point of the trigger signal curve by a linear fitting i.e. the trigger position. This method solves the paradox between traveling range and driving resolution. Experimental results show that the proposed method will avoid the permanent deformation during touching process and the repeatability of the trigger point is within 10 nm. It concludes that this trigger control method for a nano-CMM touch trigger probe not only offers the higher precision and reliability,but also shows the acceptable control efficiency.