Okay, let's analyze the easy stuff first. You have a 是 there, that you can use to split the sentence in two parts:
不断向产业链的高端提升 and 发展趋势的要求
The second one is pretty straight-forward, you have a noun phrase 发展趋势 that translates to "development trend", but even better here I think is "further development", as 趋势 carries redundant semantics in English. What it conveys here is going upward from a lower point, which is inherent in "development"; the whole thing modifies (的) the noun 要求 "requirement", "necessity", but also "precondition", therefore:
the precondition for further development
Now the hard part: here you have an adverb 不断 "continually" that (hold fast!) binds with 向 "toward". As you know, in Chinese there's a loose distinction between what in western languages we call verb and particle, so you have:
continually moving toward
Then there it goes 产业链, "industry chain" or "industrial chain" as you read here. It is not necessarily the same as "supply chain", but here english native speakers might have a different opinion. It modifies (的) the following 高端提升. This is a noun phrase as well. I agree with other posters who read 高端 as "high level" as in "high level increase", which you can simply interpret as "improvement".
Finally we put it all together:
The continual improvement of the industrial chain is precondition for further development.