The effects of parameters of Bessel-Gaussian beam on the focusing characteristics are investigated in lens system with high numerical aperture. The maximal intensity shifts from focal spot in the case of larger value of parameters of BG beam. Meanwhile, the lateral resolution is increasing with the increase of value of parameters. The effect of parameters of Bessel-Gaussian beam on the achievement of optical needle is also explored. Obviously, the value of parameters is most important to obtain optical needle.