First of all, I will explain why the call of bitcoind failed. I used Java to call the bitcoind interface through the jsonrpc. I forgot to pass the hex parameter in my Java code, so I get an error.
As far as I use https://live.blockcypher.com/btc-testnet/pushtx/ broadcast tx error, I guess is due to the site deployment bitcoind version number is not the same with me, just a guess.