Well, he does need to be voted Secretary by the Central Committee. The change that was made recently was to remove term limits - but in theory he can still be voted out. Weak sauce I know compared to judicial oversight but hey, you asked.
I agree with the GP that labeling Xi a "dictator" is hyperbole. I wouldn't even say he's as entrenched as Putin.
For any behavior you believe Xi is doing that showcase dictatorship, I can guarantee that the popular support is secured beforehand, in proportional to the impact of the actions.
Check and balanced exit, as one example, in the ways of how policies are executed between different branches and sectors.
Like if Xi wants to do some thing, the functioning branch has a great deal of influence, as the government officials are not refreshed between different government terms. Like many of Xi's policy can be effectively nullified, if the policy really were not effectively mobilizing the functioning units.
One might fancy that Xi can install his own men that is so effective that the above check is rendered ineffective. That's possible, but it seems even in the imperial era, a sane emperor was not able to do that [1]. Nor I see any evidence that Xi had acquired any such superhuman power.
These are unfortunately not as visible as western systems.
But again, I can only state qualitatively, in the sense that the check and balance is so much more effective than what a lot of people imagine. I am not an expert that can give you a systematic description of the details. I once again lament the missing of a modern day Tocqueville...
> check and balance in China
Do tell.
Last I checked, China was a one-party state and doesn't have the same judiciary-executive freedom that typically defines 'checks and balances'