The invention provides an equal-loudness contour-based loudness compensation method, which comprises the following steps of: regulating a volume of an input signal, measuring sound pressure levels corresponding to all available volume values, and in each sound pressure level, filtering an input signal by using a preset frequency filter, and multiplying by a weighting coefficient of the preset frequency filter to obtain a signal; and superposing the input signal in each sound pressure level in a plurality of sound pressure levels corresponding to all the available volume values and the signal obtained through filtering and weighting. The method overcomes the defect that when the conventional audio signal is small in volume, the loudness of partial frequency band is too low, and ears of a human body cannot feel the loudness, so that the heard sound is dry and tedious; by the method, the loudness of input signals of partial frequency band is compensated, the sound is loud and full and meets the requirement of people on acoustic comfort; moreover, a sound level meter and the filter and simple computation are only required to realize the loudness compensation of the audio signal, so that the structure is simple and the cost is low.