The China Meteorological Administration Satellite Broadcasting System (CMACast) is one of the three major meteorological data satellite broadcast systems of GEONETCast, responsible for disseminating meteorological data in the Asia Pacific region under the framework of WIS (WMO Information System) and IGDDS (Integrated Satellite Data Dissemination System). Different types of meteorological data are being broadcasted in different channels of CMACast, and channel multiplex the total bandwidth of the system based on parameters such as channel guarantee bandwidth, maximum bandwidth and priority. The data dissemination efficiency of different channels depends on the channel bandwidth allocated by the system. The larger the allocated bandwidth, the higher the data dissemination timeliness. When the amount of data broadcast in the broadcasting system is small, the system bandwidth is sufficient, and the bandwidth obtained by all channels is sufficient to meet the requirements of channel data broadcast timeliness. With the development of meteorological services, the data volume of the broadcasting system has increased from 180 GB/day to 460 GB/day. In the case of limited broadcasting bandwidth resources and varying types and sizes of broadcasting data, the accuracy of channel bandwidth parameters is having an increasing impact on the timeliness of data broadcasting. However, system managers are finding it increasingly difficult to adjust the broadcasting channel parameters to the optimal state through experience to maintain the broadcasting efficiency and timeliness of the broadcasting data. This is causing a serious decrease in the timeliness of data dissemination in some channels, which cannot meet the business timeliness requirements. By quantitatively analysing the transmission characteristics of different meteorological data, refined data transmission samples of various types of data are obtained, and the transmission characteristics of each channel data in the time domain are obtained. Based on this, scientific and quantitative calculations are being carried out for various data broadcast channel parameters according to the time requirements of each channel. Through simulation and iterative optimisation, the optimised parameters such as guaranteed bandwidth and maximum bandwidth of each channel are obtained, which are applied to business systems. This significantly improves the broadcasting efficiency of key data, optimises the overall broadcasting efficiency of the system, and solves the problem of low system broadcasting efficiency and insufficient timeliness caused by inaccurate setting of various channel parameters in the broadcast system. Through the research, a quantitative and accurate calculation and optimisation method is provided for the setting and optimisation of channel parameters in broadcast systems, solving the problem of inaccurate and difficult optimisation of channel parameters in broadcast systems using manual settings. The application is showing significant good results in practical broadcasting services.