您可以使用pattern进行验证。

<input type="password" id="pass" name="pass" pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,}" title="Must contain at least one number and one uppercase and lowercase letter, and at least 8 or more characters">

你可以学习more here
然而，如果你曾经想使用一些javascript，那么HTML5确实支持一些验证，甚至模式匹配，但我敢肯定，你需要一些javascript来让它工作，并将两个值与确认密码字段进行比较。
你可以试试这个

<input id="password" name="password" type="password" pattern="^\S{8,}$" onchange="this.setCustomValidity(this.validity.patternMismatch ? 'Must have at least 8 characters' : ''); if(this.checkValidity()) form.password_two.pattern = this.value;" placeholder="Password" required>

<input id="password_two" name="password_two" type="password" pattern="^\S{8,}$" onchange="this.setCustomValidity(this.validity.patternMismatch ? 'Please enter the same Password as above' : '');" placeholder="Verify Password" required>