As a traditional bridge type, arch bridge is widely used in the world because of its excellent mechanical performance. How to simulate the vault filling conveniently and accurately in the computer program is always a controversial topic in the bridge design industry. Taking Qinjiang River Bridge of Kaihua County as an example, two simulation methods of soil column + virtual beam method and variable cross-section continuous beam method are provided. By modeling analysis under the same conditions, the reaction force and the typical section internal force of bridge pier and abutment under the constant load and the constant load + automobile + crowd load are compared. The differences of calculation results by two simulation methods are analyzed, which give some references for the relevant practitioners.