Player cannot died when collide

In unity 2d game my when my player collide with Spike Prefab single time xso player cannot died so how i can solve this problem.

but when player collide with spike prefab simultaneously three or four time so player die.

You would need a Health script for the player first.
I made for you a Health script:

public int playerMaxHealth;
public int playerCurrentHealth;

// Use this for initialization
void Start () {
	playerCurrentHealth = playerMaxHealth;

}

// Update is called once per frame
void Update () {
	if(playerCurrentHealth < 1)
	{

		gameObject.SetActive(false);

	}

}

public void HurtPlayer(int damageToGive)
{
	playerCurrentHealth -= damageToGive;
}

public void SetMaxHealth()
{
	playerCurrentHealth = playerMaxHealth;
}

}

Attach the script to your player and set the playerCurrentHealth and maxHealth in the inspector.

Then attach this script to the spikes and set the damage in the inspector(also set the name of the Script HurtPlayer):

public int damageToGive;

// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update () {

}

void OnCollisionEnter2D(Collision2D other)
{
	if(other.gameObject.name == "Player")
	{
		other.gameObject.GetComponent<PlayerHealth>().HurtPlayer(damageToGive);
	}
}

}