In order to verify the accuracy of levitation chassis dynamics model of high speed maglev, the flexible vibration of the levitation chassis is explored, and the finite element model of levitation chassis is established to calculate its elastic mode; then the flexible-rigid dynamics model of the high-speed maglev vehicle is built. According to the field test data from Tongji University's maglev test line, the influence of flexible vibration of levitation chassis is analyzed on the gap of guidance and levitation electromagnet. The comparison with the simulation demonstrates that the results from the model of the levitation chassis flexibility is more close to the test results. The main frequencies of the vertical and lateral levitation chassis vibration are 10.4 and 13.2 Hz respectively, which are similar to modal frequencies of relative pitching and anti-phase yawing between the front and rear levitation frame. The flexibility of levitation chassis should be taken into account in the key issues of high-speed maglev trains, such as control parameter optimization, suspension parameter optimization, and running stability.