My question is regarding blood money. I want to know why the non-Muslim gets half of the blood money of the Muslim. What is the reason behind this?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His alave and Messenger.

Scholars held different opinions regarding the value of the Diyah (blood money) of the non-Muslim and whether it is the same as the Diyah of the Muslim or half or one-third of it, along with many details in this regard. Please refer to fatwa 86122.  

Part of the argument of the scholars who held that they are not equal is the following:

The sanctity of the Muslim is greater than the sanctity of the non-Muslim given the deficiency in a non-Muslim that prevents from accepting his testimony, from entitling him to inherit (from a Muslim), from marrying a Muslim woman, from receiving a share of the war spoils, and so on. Likewise, his Diyah must be less than that of a Muslim.

Also, it is a compensation for the dead person's life; so disbelief is a determining factor in decreasing the amount of the Diyah, just as in Qisaas (retribution).

For more information, please refer to fatwa 90340.

Allah knows best.