The invention provides a space mechanical arm control method based on a particle filter algorithm. The method comprises the steps that after a first control cycle of a task is over, the particle filter algorithm is used for obtaining the space position error probability distribution of the tail end of a space mechanical arm; according to the space position error probability distribution, the using reliability of the space mechanical arm is obtained; according to the using reliability and a preset reliability threshold value, an adjusting amount is obtained; according to preset first target space position information and the adjusting amount, second target space position information is obtained; and the second target space position information is space position information of the tail end of the space mechanical arm after a second control cycle is over. The invention further provides a space mechanical arm control system based on the particle filter algorithm. According to the technical scheme, the fact that the using reliability of the space mechanical arm is improved under the condition that space position error observation noise at the tail end of the space mechanical arm is in any distribution can be guaranteed.