The present invention relates to a natural gas hydrate rotary pressure-retaining corer, including an outer tube assembly and an inner tube assembly installed inside the outer tube assembly. The inner tube assembly includes an inner tube assembly a and an inner tube assembly b. The inner tube assembly a includes a spearhead, a latch mechanism, a long tube, a middle tube sub, a short joint, a sealing sub, a connecting tube, a middle tube and a pressure-retaining ball valve closing sealing mechanism connected sequentially from top to bottom. The inner tube assembly b includes a lifting device, a latch suspension mechanism, an spirol pin sub, a single-action mechanism, a dapter, an adjustment joint, a connecting tube, a sealing mechanism, a connecting long tube, a connecting long tube sub and a core barrel connected sequentially from top to bottom.