要使Intersect方法正确识别自定义类型，需要实现IEqualityComparer接口来对自定义类型进行比较。以下是一个示例代码：

```csharp

using System;

using System.Collections.Generic;

using System.Linq;

class Program

{

static void Main()

{

List list1 = new List

{

new Student { Id = 1, Name = "Alice" },

new Student { Id = 2, Name = "Bob" },

new Student { Id = 3, Name = "Charlie" }

};

List list2 = new List

{

new Student { Id = 2, Name = "Bob" },

new Student { Id = 4, Name = "David" },

new Student { Id = 5, Name = "Eve" }

};

var intersectedStudents = list1.Intersect(list2, new StudentComparer());

foreach (var student in intersectedStudents)

{

Console.WriteLine($"Id: {student.Id}, Name: {student.Name}");

}

}

class Student

{

public int Id { get; set; }

public string Name { get; set; }

}

class StudentComparer : IEqualityComparer

{

public bool Equals(Student x, Student y)

{

return x.Id == y.Id && x.Name == y.Name;

}

public int GetHashCode(Student obj)

{

return obj.Id.GetHashCode() ^ obj.Name.GetHashCode();

}

}

}

```

在这个示例中，定义了一个Student类，并实现了IEqualityComparer接口来比较两个Student对象。然后，在Main方法中，创建了两个Student对象的列表，并使用Intersect方法找到两个列表中共同存在的元素。