建立了链表，如果输入其他数字都可以判断是否有这个编号，但是输入0的时候
如果没有编号为0的节点，就会删除最后一个节点。
这是为什么呢？

你贴上你的程序让大家看看，才好帮你。

struct Student * Delete(struct Student *p)
{
    struct Student * p0, *p1;
    int i;
    printf("Please enter a integer to number for delete sequence.\n");
    while (scanf("%d", &i) !=1 )
    {
        while (getchar()!='\n')
            continue;
        printf("Please enter a integer again!\n");
    }
    if (i == p->sequence)
    {
        p0 = p->next;
        printf("Delete NO.%d!\n", i);
        return p0;
    }
    p0 = p;
    while (i != p->sequence && p->next != NULL)
    {
        p1 = p;
        p = p->next;
    }
    if (p->sequence == i)
    {
        p1->next = p->next;
        printf("Delete NO.%d!\n", i);
    }
    else
        printf("You enter is error!Try again!\n");
    return p0;
}

struct Student * Delete(struct Student *p)
{
    struct Student * p0, *p1;
    int i;
    printf("Please enter a integer to number for delete sequence.\n");
    while (scanf("%d", &i) !=1 )
    {
        while (getchar()!='\n')
            continue;
        printf("Please enter a integer again!\n");
    }
    if (i == p->sequence)
    {
        p0 = p->next;
        printf("Delete NO.%d!\n", i);
        return p0;
    }
    p0 = p;
    while (i != p->sequence && p->next != NULL)
    {
        p1 = p;
        p = p->next;
    }
    if (p->sequence == i)
    {
        p1->next = p->next;
        printf("Delete NO.%d!\n", i);
    }
    else
        printf("You enter is error!Try again!\n");
    return p0;
}

你的函数只能删除一个节点，输入时的while 是不需要的，去掉那个while 就行了。如果想删除多个，底下部分放在循环之内。
struct Student * Delete(struct Student *p)
{
    struct Student * p0, *p1;
    int i;
    printf("Please enter a integer to number for delete sequence.\n");
    scanf("%d", &i);
    if (i == p->sequence)
    {
        p0 = p->next;
        printf("Delete NO.%d!\n", i);
        return p0;
    }
    p0 = p;
    while (i != p->sequence && p->next != NULL)
    {
        p1 = p;
        p = p->next;
    }
    if (p->sequence == i)
    {
        p1->next = p->next;
        printf("Delete NO.%d!\n", i);
    }
    else
       printf("学号不再其中!\n");
    return p0;
}