Public offering refers to the public offering of securities by issuers through intermediaries. In the case of public offering, all legal social investors can participate in the subscription, including individual investors, legal institutions and securities investment funds. In order to protect the interests of investors, all countries have strict requirements for public offering. For example, the issuer must have a high credit and meet the various issuance conditions stipulated by the securities authorities before it can be issued. In China, the public offering of shares must comply with the relevant provisions of the Securities Law and the Company Law.