Abstract: The liquid crystal tunable filter (LCTF) is used as micro spectrometer in many measuring fields for its simple and efficient light filter function. But the spectral resolution of LCTF is limited by its bandwidth, and the hardware cost and larger measure data are the problem in higher resolution measuring. In this paper, combining the compressive sensing with the LCTF spectral measuring method, a new model was proposed to get the object spectral curve with a superior spectral resolution than the system bandwidth. In the model, the data calculation of LCTF spectral measurement was correlated with its transmittance function of corresponding wavelength. Analysis results show that, the measurement matrix in the proposed model possesses a good incoherence property. The simulation results of real earth object's spectrum show that, the spectral curve of 128 band pearl stone can be reconstructed with only 32 measurements, the mean error of reflectance is only 0.75% with a certain noise repellency, and the spectral details can be distinguished while traditional method cannot work.