Gold nanoparticles are widely employed in nanomaterials, nanobiotechnology and health care, but generally they are
considered difficult to trap stably. Compared with the continuous laser which is popular to the optical trapping, pulse
laser has a relatively larger power in its work pulse, which is useful for trap particles. So this paper comprehensively
analyzes the forces (the radiation forces, the gravitation, and the Brownian motion) on the gold nanoparticles in the
optical tweezers formed by a pulse laser, through building up a mathematical model. Finally gets the dependence relation
between the characteristics of the pulse laser and that of the gold nanoparticles.