An equivalent refractive mathematic model is presented according to the geometrical structure of twin-hole poling optical fibers. The characteristics of losses and polarizations of the fibers are theoretically analyzed. The theoretical analysis and experimental results indicate that when the metal electrode is close to the fiber core, the loss of y-polarization mode is far lower than that of x-polarization mode, and the electrode-manufacturing method of inserting metal wires has better loss performance than that of injecting melting alloys. (The former is less than 0.04 dB/cm, and the latter is 2.5 dB/cm.) The experimental measurements agree well with the theoretical predictions.