Sun Zhang said that construction of China’s HSR enjoys a technological advantage of the runner-up in terms of integrating technologies we have bought from the advanced countries all at once, so it can be said that China has everything that is required for building HSR system, besides the advantage of low cost.
The "runner-up" is the person who comes in second in a race. The meaning here is that other companies have invented the technology (won the race), but HSR can use that to their advantage by buying and integrating those technologies.