对装有JZ—7型空气制动机的东风4型机车时而发生自然制动的现象进行了分析，找出了原因，介绍了处理方法。并建议将制动缸缓解弹簧的弹力在原有基础上增加一个适当的值，这样才能使其有足够的力量去克服阻力，完成推回鞴鞴的任务，消除司机难以发现与处理的机车制动难题。 The phenomenon of natural braking sometimes occurs in Dongfeng 4 locomotive equipped with JZ-7 airbrake, the reason is found, and the treatment method is introduced. And suggested that the brake cylinder relieve the spring force on the basis of the original to add an appropriate value, so as to make it have enough power to overcome the resistance, to complete the push back 鞴 鞴 mission to eliminate the driver difficult to find and deal with the locomotive brake problem.