A smart method to induce tunable long-period fiber gratings (LPFGs)based on the mechanical minor bend effect is studied. The effects of factors in this method on the tunable LPFGs are further analyzed. It is found that the change rate of resonant wavelength is about 17.7 nm/0.01mm. Only increasing the pressure,the loss peak would increase firstly and can be tuned to 16.248 dB. If the pressure is increased beyond a certain point,the loss peak would decrease. The added loss increases with the increasing pressures. And when the pressure is fixed,the loss peak would decrease with the increase of the period number of grooved plate. The results are propitious to flexibly apply LPFGs to gain flattening in EDFA and filtering.