The invention relates to a linear output detection method of a weak coupling resonant type sensor based on modal localization, and belongs to the field of MEMS. The method specifically comprises the following steps: step 1, determining whether double resonators are in an in-phase driving state or an inverted-phase driving state, if in the in-phase driving state, selecting the first-order mode as the working mode, if in the inverse-phase driving state, selecting a second-order mode as the working mode; step 2, detecting the amplitude difference (|X1 (j omega)-X2(j omega)|) of the two resonatorsto obtain the relation between the amplitude difference and the to-be-detected amount. The invention provides a linear output method of the weak coupling resonant type sensor based on modal localization, the amplitude difference of the two resonators under the driving condition of the double resonators is adopted instead of the amplitude ratio as the output of the sensor, and the output linearization of the weak coupling resonance type sensor at the two sides of the separation point is realized for the first time.