Here , https://check.torproject.org/exit-addresses ,the site contains all tor exit node ,i just need to know who update those list? Is it automatic?
Yes it's automatic. A super simple explanation is that Tor relays make themselves known to the the network by announcing themselves on the network and then special relays called Directory Authorities (they're identities are hard-coded into the Tor source) vote on all the relays based on feedback and observation from other relays. Eventually, if your configuration allows it and uptime, bandwidth and other factors look good, the Directory Authorities will promote that relay to an "Exit" (this takes time and doesn't happen right away).
Since the network keeps track of what relays will permit exit traffic, a list of exit addresses can be built from that consensus.
There are tons of other sites that also build and publish these lists with other miscellaneous information about the relays.
But to answer your question, yes, those exit addresses are published automatically, are are accurate since its a dump of relays that are flagged as Exit relays on the network.