Styles values in Baidu Maps URL are meaningless and there are no docs about them. So you better guess them.

GetBaiduMapsStyles.sh

#!/bin/bash

mkdir -p m

for l1 in a b c d e f g h i j k l m n o p q r s t u v w x y z
do

for l2 in a b c d e f g h i j k l m n o p q r s t u v w x y z
do

echo -ne "  Trying $l1$l2... \r"
curl "http://online$((RANDOM%9+1)).map.bdimg.com/tile/"\
"?qt=tile&x=12320&y=2567&z=16&styles=$l1$l2" -L -s -o m/$l1$l2.png

done

done