Yes, there are multiple flights from Thailand to Shenyang for under ฿12,471. The cheapest flight booked recently is on XiamenAir for just ฿9,977, but on average you can expect to pay ฿18,863.
China Southern is one of the carriers that may have flexible change policies. You can use our site to filter for other airlines that may also have this kind of flexibility.
There are no direct flights from Thailand to Shenyang, but Cheapflights can provide you with all the information you need to find the fastest route with the fewest stops.
According to our current data, XiamenAir (฿9,978), offers the cheapest pricing from Thailand to Shenyang.