At risk of being politically incorrect, China has some of the highest quality human capital in the world per capita. Add in their huge population and they have roughly 20 times the number of people capable of high-level technical research. China, frankly, has little need of immigration. It's technical dominance is assured without it.
This comment from nopinsight goes through the scores:
Key competitive advantages of China are their strength in quantitative skills as well as huge population and the hard working and competitive culture of its populace. An objective measure is PISA results [1]. When comparing with even the best performing US state, Massachusetts, China has many more top performers in Math, as a proportion of population [2].
(In 2015 only four provinces of China participated, but their combined population was 230 million vs Massachusetts's 6.8 million. The math result of Shanghai (24 million pop.) alone would show an even larger gap.)
Since PISA results are scaled such that OECD country's mean is 500 and standard deviation is 100. China's 531 math score implies country mean at 0.3 SD above PISA mean, and US' math score at 470 implies 0.3 SD below mean. If people capable of doing AI research or proper AI implementation need to have math skills at, say, 2 SD above PISA mean, then there will be a tremendous difference in proportion between two populations with 0.6 SD difference. My back-of-the-envelope calculation, assuming above figures, is the difference in proportion will be about five times. But China has more than 4 times the population of the US, so the difference in potential numbers of AI-capable natives could be over 20 times. (Since other provinces may drag down China's mean, it could be a bit less. We'll see soon since China as a whole will participate in 2018.)