There is really only one Australian export which China really needs, and that's iron ore.* More than 60 per cent of China's iron ore imports come from Australia and its other major supplier — Brazil — is in a world of trouble because of COVID-19 in its mines and a tailing dam collapse. So if we suddenly stopped sending them iron ore, many of their larger steel mills would probably stop operating. That would deliver a substantial blow to China's economy.
But there's no way Australia would do that because we'd lose a market worth tens of billions of dollars. That would be a hammer blow to our economy, which is only just starting to emerge from the coronavirus crisis.
Earlier this year the Nationals leader Michael McCormack declared "we need China as much as China needs us" but unfortunately that's probably not true. The brutal reality is we simply do need China, more than they need us. This doesn't mean we should just fold to Beijing's demands of course. But they hold more cards than we do.
*Australian coal is also quite important and there are another one or two which are quite crucial to supply chains but that's a more complicated story.