Abstract: With the rapid expansion of deep exploration layers in domestic oil and gas exploration targets, more stringent requirements have become necessary in terms of signal-to-noise ratio, resolution, and imaging accuracy of seismic data.Therefore, geophones with higher sensitivity and bandwidth performance are needed.In this work, a distributed feedback fiber laser (DFB-FL) with a narrow linewidth and low noise is used as the sensing element.An all-fiber three-component fiber laser geophone for downhole exploration is developed on the basis of the vibration sensing units, and a coherent detection method is adopted to detect weak seismic signals.Frequency response sensitivity and noise tests were carried out in the laboratory, and a comparison with the high-temperature moving-coil geophone 2400 is carried out.The temperature and pressure resistance performance of the downhole fiber optic geophone are also evaluated.The experimental results show that the three-component fiber laser geophone has good signal detection capability within 1~400Hz, the sensitivity reaches 34dB re pm/g, the cross sensitivity is less than -25dB, and it can withstand temperatures as high as 155℃ and pressures up to 50MPa.The advantages of the three-component fiber laser geophone are its compact structure, high sensitivity, wide-band frequency response, good consistency, high temperature and pressure resistance, and good application prospects in underground exploration and other harsh working environments.