Initial Orbit Determination （IOD） is a difficult problem in space-based optical space surveillance. Based on a discussion of the reason for the convergence of the calculation results converge to the trivial solution， an improved IOD procedure that eliminates the trivial solution is proposed. By constructing the 8th polynomial equation of the Laplace method， the relationship between the properties of coefficients and roots when the space target is at different relative positions is analyzed. For the phenomenon that the classical Laplace-type IOD method converges to the orbit of observation platform， the mathematical characterization and numerical verification of the trivial solution are given， and an elimination method is proposed. Since the IOD method using distance search based on the Lambert problem is relatively sensitive to the initial value of space-based target monitoring， the Gooding method is modified by the trivial solution elimination method， and a new method suitable for IOD of space-based space targets is proposed. Finally， the method is verified by measured data of low Earth orbit target monitoring and simulation data of geosynchronous orbit target monitoring. The results show that this method can effectively solve the trivial solution and initial value sensitive problems. The method has the characteristics of fast convergence speed and reliable accuracy， and is thus universal， easy to understand and generalize.