Method for switching between different systems in CDMA communication system

The invention discloses a process for realizing cross-system switching in a CDMA communication system wherein, the method for controlling the compression mode can substantially reduce the usage frequency of the compression mode in the iso-system measurement, thus reducing the influence to the system performance by the compression mode. By adopting the method of activating multiple compression pattern in the iso-system measurement, the use of transmitting instructions is substantially reduced, thus the system performance is optimized. The CDMA mobile telecommunication system applying the present invention may configure multiple compression patterns in the iso-system measurement without overlapping, so the reasonability and accuracy for the compression pattern configuration is assured, preventing the ping-pang switching caused by the signal fluctuations.