A map constructing method, characterized in that the method comprises: acquiring a trajectory map to be matched Mvi; searching for a matched trajectory map Ms that matches with the trajectory map to be matched Mvi; whereby the trajectory map to be matched Mvi refers to a trajectory map uploaded by a vehicle or other terminals, and the matched trajectory map Ms refers to a trajectory map pre-stored in a server; performing map-element matching transformation between the trajectory map to be matched Mvi and the matched trajectory map Ms according to road-sign data, wherein the map element matching refers to selecting a road sign in the trajectory map to be matched Mvi, and subsequently finding a road sign same as or similar to the selected road sign from the matched trajectory map Ms, wherein after the map-element transformation, the trajectory map to be matched Mvi and the matched trajectory map Ms are referred to as a map Mvi-X1 and a map Ms-X1 respectively; performing road-sign matching transformation between the map Mvi-X1 and the map Ms-X1 according to road data, wherein the performing road-sign matching transformation between the map Mvi-X1 and the map Ms-X1 comprises: matching road data; matching road signs contained in matched roads in the map Mvi-X1 and the map Ms-X1; according to data of matched road signs, calculating a road transformation matrix; and according to the road transformation matrix, performing rotation and translation to the map elements of a matched road in the map Mvi-X1 and the map elements of a matched road in the map Ms-X1, wherein the matching road data refers to selecting a road in the map Mvi-X1, and subsequently finding a road same as or similar to the selected road from the map Ms-X1, wherein after the road-sign matching transformation, the map Mvi-X1 and the map Ms-X1 are referred to as a map Mvi-X2 and a map Ms-X2 respectively; fusing characteristic data of road signs matched in the map Mvi-X2 and the map Ms-X2 by using a weighted averaging method, and replacing corresponding characteristic data in the map Ms-X2 by using the characteristic data of the road sign obtained after the fusion, wherein the map Ms-X2 whose characteristic data of the road sign have been replaced is referred to as a map Ms-X3; and adding roads and road map elements in the map Mvi-X1 that are not able to be matched into the map Ms-X3, wherein the map Ms-X3 with the added roads is referred to as a map Ms-X4. acquiring a trajectory map to be matched Mvi; searching for a matched trajectory map Ms that matches with the trajectory map to be matched Mvi; whereby the trajectory map to be matched Mvi refers to a trajectory map uploaded by a vehicle or other terminals, and the matched trajectory map Ms refers to a trajectory map pre-stored in a server; performing map-element matching transformation between the trajectory map to be matched Mvi and the matched trajectory map Ms according to road-sign data, wherein the map element matching refers to selecting a road sign in the trajectory map to be matched Mvi, and subsequently finding a road sign same as or similar to the selected road sign from the matched trajectory map Ms, wherein after the map-element transformation, the trajectory map to be matched Mvi and the matched trajectory map Ms are referred to as a map Mvi-X1 and a map Ms-X1 respectively; performing road-sign matching transformation between the map Mvi-X1 and the map Ms-X1 according to road data, wherein the performing road-sign matching transformation between the map Mvi-X1 and the map Ms-X1 comprises: matching road data; matching road signs contained in matched roads in the map Mvi-X1 and the map Ms-X1; according to data of matched road signs, calculating a road transformation matrix; and according to the road transformation matrix, performing rotation and translation to the map elements of a matched road in the map Mvi-X1 and the map elements of a matched road in the map Ms-X1, wherein the matching road data refers to selecting a road in the map Mvi-X1, and subsequently finding a road same as or similar to the selected road from the map Ms-X1, wherein after the road-sign matching transformation, the map Mvi-X1 and the map Ms-X1 are referred to as a map Mvi-X2 and a map Ms-X2 respectively; fusing characteristic data of road signs matched in the map Mvi-X2 and the map Ms-X2 by using a weighted averaging method, and replacing corresponding characteristic data in the map Ms-X2 by using the characteristic data of the road sign obtained after the fusion, wherein the map Ms-X2 whose characteristic data of the road sign have been replaced is referred to as a map Ms-X3; and adding roads and road map elements in the map Mvi-X1 that are not able to be matched into the map Ms-X3, wherein the map Ms-X3 with the added roads is referred to as a map Ms-X4.