The answer to this question may vary depending on your locality (aka jurisdiction), however in most cases anyone may purchase a life insurance policy provided that they have a legitimate interest to insure.
In your case, because the policy would be taken out in regards to your husband, you definitely have an insurable interest - which means you could likely take out the policy without his knowledge.
of course you can buy life insurance on your husband without he knowing.before that you have to submit you husband legal document like passport or any other legal identified document photo copy .next steep you need to give your all information and you have to sign the paper.
Yes you can take out insurance on your husband. You would designate yourself as the owner and payor of the policy. Owner retains all rights to the policy can make changes to beneficiaries and to how the product is paid. Owner also has the right to cash in or take loans out against cash value policies. As the Owner you will be able to make yourself the beneficiary and anyone else you would like as the secondary beneficiary.
You will unfortunately have to get your husband to answer questions for the insurance company and to take any physicals or exams for the coverage as the insurer requires. You're husband will also have to sign the contract as the insured. Unless he signs over a power of attorney to you, in which case you can sign as the insured on your husbands behalf.
Bottom line you can take the insurance out on him but it will be next to impossible to do so without him being aware.