Abstract: The theory model of Compass triple-frequency geometry-free combination used for cycle-slip detection is deduced, and the detection accuracy is analyzed. Based on the theory of multi-frequency combination, some optimal geometry-free combinations for detecting cycle-slip have been constructed, the insensitive cycle-slip groups of the detection observables have been analyzed. In order to detect all the cycle-slips, two proper geometry-free combinations are simultaneously used to be as the detection observable combination, the better detection observable combinations have been selected. Because the cycle-slips on the three frequencies observations cannot be determined by two linear independence geometry-free combinations, the method of cycle-slip correction by geometry-free detection observable combination and one combination of pseudo range and carrier phase observations has been explored. Using the real Compass triple-frequency data, finally several experiments have been made to test the effect of using (-1,-1,2) ,(-1,2,-1) geometry-free combinations and the (1,3,-4) combination of pseudo range and carrier phase observations. Experiment results show that this method is effective，practical and can be used to the kinematic navigation positioning which can detect all the cycle-slips, no matter the small one or the big, and can correct the cycle-slip based on single epoch.