You must allow your landlord access to your home if they need to inspect it for the purposes of repairs. They should give you reasonable notice (usually at least 24 hours) before coming round, unless it’s an emergency.
Landlords only have the right to enter the parts of your home that need repair work done. If they need to fix the kitchen sink, for example, it doesn’t mean that they can look round the rest of your home without your permission.
Your landlord should not need to come round very often to inspect the property. If they are coming more often than you would like, or letting themselves in without your permission, it could be considered harassment.
Try to speak to them and agree how often it is acceptable to have the property inspected. If you are unable to reach an agreement, or if your landlord does not keep to an agreement that you have made, get advice.