Vector sensors show great value in various applications because they can synchronously measure vector information such as vibration velocity, acceleration and so on in a single place with a certain level of ability for noise suppression. Erbium/Ytterbium co-doped fiber lasers can be employed to implement miniature, multiplexing friendly and highly sensitive fiber sensors without the need for complicated demodulation schemes. For such kind of sensors, an accelerometer structure is proposed, which realizes a dual frequency interference based fiber grating laser vector sensor for acceleration through restrictions of the transversal movement of the mass in the structure. Besides those merits possessed by dual-polarization fiber lasers, it shows quite good directional characteristics in ′8′ shape with flat frequency response below 1 kHz, which presents an important reference for implementations of dual frequency interference based fiber vector sensors.