The invention relates to a method for evaluating fatigue performance of a concrete pavement layer on an orthotropic steel bridge deck, in particular to a device for evaluating fatigue performance. According to the scheme, the method comprises an elastic pressure head loading method simulating wheel loads of an automobile, a steel plate-concrete pavement layer composite beam test piece forming method, a support form simulating stress of U-type ribs on the steel bridge deck, an elastic support for simulating the condition of a real bridge and a composite beam response acquisition and analysis scheme; evaluation indexes comprise fatigue life, stress, deflection and the like of a composite beam. The device can simulate the stress condition of the orthotropic steel bridge deck under the action of wheel loads and can be used for comprehensively and quantitatively evaluating the response condition and the fatigue performance of the concrete pavement layer on the steel bridge deck. The test method is reasonable in design, detailed, accurate and specific, the evaluation method is scientific and systematic, and the operability is higher.