The 'bound 2' hitmaker "constantly worries" about his wife and their 17-month-old daughter North so does everything he can to keep them safe, says his step-brother, Hal Carmichael.
In an interview with new issue of heat magazine, Hal said: "Kanye constantly worries about Kim and North because he knows the kidnap risk is high.
"Because of the lifestyle they lead, he has to think about it carefully nowadays.
"Kanye controls Kim, like where she travels and what she does, to protect her. He thinks the more the public see of them, the more at risk they are."
Kanye knows Kim's job requires her to be in the public eye, but he tries to limit the people around them in a bid to keep them extra safe.
Hal added: "Kanye and Kim want to be the next big power couple and that comes from exposure.
"Kim being on television is a compromise, but Kanye knows that's her career and he'll support her.
"Kanye keeps his inner circle tight - with North she'll only be looked after by her grandmother Kris [Jenner] or her aunties.
"They have a nanny as well, but North is kept around family. Kanye does this to protect her."
And even when they visit their relatives, the couple are still accompanied by two security guards.
Hal - whose mother Cheryl married Kanye's dad Ray in 1997 - said: "They always have two security guards with them. Even when he went to our sister's last month, he took them with him and they drive around in armoured cars.