1. A method for three-dimensional (3D) operation control of a touch screen, wherein an axis along a first direction is an X-axis, a Y-axis is perpendicular to the X-axis, and a Z-axis is perpendicular to both of the X-axis and the Y-axis, the method comprising: acquiring capacitance values of at least two acquiring points in a motion trajectory formed by a finger or a conductor moving in a touch screen sensing space, wherein a region projected by each of the acquiring points to the touch screen intersects with at least two electrodes, the capacitance values of each of the acquiring points are capacitance values of capacitors formed by the finger or the conductor and the at least two electrodes in the projection region respectively when the finger or the conductor approaches to the touch screen; calculating coordinates of the acquiring points on the X-axis, the Y-axis and the Z-axis respectively according to formulas of X=f(C A ,C B ), Y = ∑ Ci · Yi ∑ Ci and Z = ɛ × A ∑ C th. to obtain 3D coordinates of the acquiring points, where, C A is a capacitance value formed by a first kind of triangular electrodes in the region projected by each of the acquiring points onto the touch screen as detected by an A channel in the touch screen, C B is a capacitance value formed by a second kind of triangular electrodes in the region projected by the acquiring point onto the touch screen as detected by a B channel in the touch screen, Ci is a capacitance value formed by an electrode in the region projected by the acquiring point onto the touch screen as detected by one of the channels, Yi is a position coordinate defined in the Y-axis direction by one of the electrodes in the region projected by the acquiring point onto the touch screen, each of the channels in the touch screen is connected to a corresponding electrode respectively and can detect the capacitance value formed by the corresponding electrode, the A channels refer to all channels connected with the first kind of triangular electrodes in the touch screen, the B channels refer to all channels connected with the second kind of triangular electrodes in the touch screen, A represents an area of each of the acquiring points, ∈ represents a dielectric coefficient, ΣC th represents a capacitance change between the capacitance value of the acquiring point and an original capacitance value of the projection area, and the original capacitance value of the projection region refers to a capacitance value of the electrode in the projection region when no finger or conductor approaches to the touch screen; and determining the motion trajectory according to the 3D coordinates of the at least two acquiring points, and executing a corresponding operation.