The invention discloses a method for carrying out high-precision relative navigation based on GNSS through employing a single receiver, and the method comprises the following steps: 1, making preparation; 2, determining the position of the receiver and a clock error at an initial moment; 3, searching a public visible satellite at a current epoch moment and a former epoch moment; 4, building a carrier epoch single-difference model; 5, setting an initial estimation value and a calculation constant at a current moment; 6, calculating the position of the receiver and the clock error at the current moment; 7, judging whether the calculation result meets the requirements or not; 8, updating a position estimation value and a clock error estimation value 9, judging whether the current moment is the last epoch or not. The carrier epoch single-difference model is built through the above flow, and a single-point positioning method is used as assistance. The method achieves the high-precision navigation through a relative positioning method, and the method is implemented through the single receiver, so the method has low requirements, is low in cost, and facilitates the popularization and application.