Based on the product platform of QuantumCTek, the Industrial and Commercial Bank of China has successfully applied the quantum communication technology to the Beijing-Shanghai offsite wide area network application under the framework of "two cities and three centers". Quantum encrypted transmission of Beijing-Shanghai offsite data is achieved for online banking service. This is for the first time among the world, that banking industry has applied quantum communication technology at a level of one-thousand kilometers, which marks an important milestone for quantum communication going into practice in China.