<qa>  What is the new method to therapy secondary hyperparathyroidism?Microwave ablation, as a new method to therapy secondary hyperparathyroidismSHPT, now is developing rapidly. However, it is still unknown whether it is effective to accept microwave ablation for hemodialysis patients with mild-to-moderate SHPT. In this prospective, randomised control and paried clinical trial study, the investigators will observe the efficiency and safety of microwave ablation in hemodialysis patients with mild-to-moderate secondary hyperparathyroidism. The patients in age-matched control group will accept active Vitamin D therapy. 