Fluorescence polarization (FP) signal is a self-referencing fluorescence signal, and it is less dependent on dye concentration and environmental interferences, which makes FP measurement a highly attractive alternative sensing technology to conventional fluorescent detection methods. Here we adopted a strategy for rapid increase of molecular weight to increase the FP signal for the detection of meat adulteration. The molecular weight of fluorescent labeled primers increased rapidly by slight preamplification, and the FP values were varied accordingly. We found a positive correlation between adulteration ratio and the FP signals. Detection limit for adulterated beef can be reached as low as 0.1% (wt %), meeting or better than the most detection requirements. On the basis of this proposed amplification-integrated FP method, both the standard samples and the commercial processed beef samples were successfully authenticated with satisfied results.