You haven't mentioned your device but being a question on frequent updates was browsing Xiaomi forums and here is a very similar question for Redmi Note 3 asked and answered yesterday- you need to sign up
Question asked (edited)
But getting "Updates available" message very often and none of them are less than 125MB and almost all of them are Stable.
Two weeks back i got an update. I did it. And today (26th June - 2016) one more update. Called "Bug fixes".
Why am i getting this often? Is that only me? Should i go for it?
Reply from MIUI device team
Updates are normally to fix issues so is generally good to install them. If you are on the Stable ROM you should not get updates that often but the Developer ROM can be a few a month.
Updates to the System get installed in the System partition not user areas anyway but generally they overwrite existing files anyway so does not use extra space anyway.
So you have it from the OEM that it is safe, and being on developer ROM, you should expect and get frequent updates