The utility model provides a free vibration device loose deeply in the agricultural machine field, including the installation roof beam, be equipped with free vibration subsoiler on the installation roof beam and construct, free vibration subsoiler constructs including subsoiler, and subsoiler's top fixed mounting has the bearing frame, and the vibration axle is installed to the bearing frame fit in, vibrates the epaxial eccentric wheel that is connected with, the utility model discloses make subsoiler produce free vibration, subsoiler can not draw the pressure circulation because of the forced oscillation production and warp, and can save the tractor traction resistance, and the improvement is pine efficiency deeply, and it can be used to the field piece high to dark loose depth requirement, that the soil moisture conservation expects much.