We propose and fabricate a high-sensitivity vector vibration accelerometer with a multicore fiber Bragg grating Fabry-Perot (FBG-FP) structure. The acceleration sensitivities of the FBG and FBG-FP are 0.15 and 1.26 V/g, respectively. After packaging, the acceleration sensitivity of the FBG-FP is further improved to 6.89 V/g, which is 45.9 times higher than that of the FBG. The resonant frequency of the accelerometer increases from 30 to 86 Hz. Both the sensitivity and resonant frequency of the accelerometer are improved. Owing to the asymmetry of the outer core of the multicore fiber, high-sensitivity two-dimensional vector acceleration sensing can be realized.