Physics cross sections and event generation of e + e − annihilations at the CEPC

The cross sections of the Higgs production and the corresponding backgrounds of e~+e~- annihilations at the CEPC(Circular Electron and Positron Collider) are calculated by a Monte-Carlo method, and the beamstrahlung effect at the CEPC is carefully investigated. The numerical results and the expected number of events for the CEPC are provided.