diff --git a/src/Application/TakeoutSaaS.Application/App/Tenants/Commands/SelfRegisterTenantCommand.cs b/src/Application/TakeoutSaaS.Application/App/Tenants/Commands/SelfRegisterTenantCommand.cs
index 259a004..cddd7ed 100644
--- a/src/Application/TakeoutSaaS.Application/App/Tenants/Commands/SelfRegisterTenantCommand.cs
+++ b/src/Application/TakeoutSaaS.Application/App/Tenants/Commands/SelfRegisterTenantCommand.cs
@@ -14,6 +14,7 @@ public sealed record SelfRegisterTenantCommand : IRequest<SelfRegisterResultDto>
     /// </summary>
     [Required]
     [StringLength(64)]
+    [RegularExpression("^[A-Za-z0-9]+$", ErrorMessage = "登录账号仅允许大小写字母和数字")]
     public string AdminAccount { get; init; } = string.Empty;
 
     /// <summary>
diff --git a/src/Application/TakeoutSaaS.Application/App/Tenants/Validators/SelfRegisterTenantCommandValidator.cs b/src/Application/TakeoutSaaS.Application/App/Tenants/Validators/SelfRegisterTenantCommandValidator.cs
new file mode 100644
index 0000000..411d834
--- /dev/null
+++ b/src/Application/TakeoutSaaS.Application/App/Tenants/Validators/SelfRegisterTenantCommandValidator.cs
@@ -0,0 +1,22 @@
+using FluentValidation;
+using TakeoutSaaS.Application.App.Tenants.Commands;
+
+namespace TakeoutSaaS.Application.App.Tenants.Validators;
+
+/// <summary>
+/// 自助注册租户命令验证器。
+/// </summary>
+public sealed class SelfRegisterTenantCommandValidator : AbstractValidator<SelfRegisterTenantCommand>
+{
+    /// <summary>
+    /// 初始化验证规则。
+    /// </summary>
+    public SelfRegisterTenantCommandValidator()
+    {
+        RuleFor(x => x.AdminAccount)
+            .NotEmpty()
+            .MaximumLength(64)
+            .Matches("^[A-Za-z0-9]+$")
+            .WithMessage("登录账号仅允许大小写字母和数字");
+    }
+}