Research conclusions: The angle deformation will appear when gauss projection is used in coordinate projection division of the different central meridians，which has a negative impact on the tack design of high—speed railway．Especially when the rectilineal side of high—speed milway is very long，this negative impact Call not be ignored．This impact on the track design of high—speed railway should be reduced by some ways，such as optimizing the position of the subdivision of projection of engineering independent coordinate and controlling the deformation sizes of the central meridian span and angle of adjacent gauss projection divisions．And also it is necessary to research the projection model and calculation method for the engineering survey to achieve the goal that only one projection division is used in a engineering project or fewer divisions are used in one engineering project