点击Your Account---Manage Your Prime Membership
我的没注册所以看不到，如果有注册的且付费，点击End membershi，在页面左手边，如果取消试用会有End membership。
You can end your Amazon Prime membership, or cancel your free trial
to ensure it doesn't convert to a full Amazon Prime membership, in the Settings section of Your Account.
To end your Amazon Prime membership or cancel your free trial:
Go to Manage Your Prime Membership.
Depending on whether you have a paid Amazon Prime membership or are on a free trial, do one of the following:
To end a paid membership, click End membership, on the left-hand side of the page.
Note: Paid members who haven't used their Amazon Prime
benefits, including Premium Delivery, Prime Video, and the Kindle
Owners' Lending Library in the then current paid period will be eligible
for a full refund for that period.
To cancel a free trial, click Do not continue, on the left-hand side of the page.
Note: If you select Do not continue
for your free trial, you'll receive benefits until your free trial
period ends. Then your membership will cancel, and your payment card
won't be charged. If you decide later in the free trial to continue your
membership after the free trial period, you can change this setting
back by clicking Continue membership. You can opt out at any time during the free trial period.