It is Qing dynasty Decollating Dao as what brother Leng said.The bottom one is used to decollate people,the two piece above are used to put to death by dismembering the body.

• 却如冷兄所言为清代刑刀，最下面的一把为砍头之用，上面的两柄为凌迟之用，上面的资料说在明代就可以剐1000多刀了。