The invention provides a cursor positioning method and device and a cursor control method and device. The method comprises the steps that S1, a displayer is equally divided into sub-regions in a preset quantity, and all the sub-regions flicker at different frequencies; S2, an electroencephalogram signal sent by an electroencephalogram collection processing device is received, wherein the brain electric signal is obtained after the brain electric collection processing device collects the brain electric signal of a user watching the displayer; S3, the brain electric signal is processed and analyzed, and a first sub-region is determined from all the sub-regions to serve as a watching region of the user according to the processing and analysis result; and S4, the steps S1, S2 and S3 are repeated, the first sub-region is divided, and when the number of times of division is greater than a preset threshold value, the first sub-region is determined as a cursor clicking position. Through the embodiment, the control efficiency of a cursor is improved, the operation steps better conform to a natural selection reaction of the user, and natural interaction between the user and a computer can be realized.