Taking a three-tower self-anchored suspension bridge as the research object, based on the data of Three-tower Self-anchored Suspension Bridges built at home and abroad, the Economic performance of the Three-tower Self-anchored Suspension Bridge is studied, the conception of materials consumption with structural parameters and mechanical property is established. And the effects of the material of girder, rise-span ratio, side to center span ratio for the total cost are studied. Come to the conclusion that changing the material of girder has much impact on the cost of three-tower self-anchored suspension bridge; Increasing the rise-span ratio can reduce the cost of main cable significantly; The side to center span ratio should be the largest value in the reasonable scope when the total length of a bridge has been defined.