How to evaluate the noise figure of a wireless receivers with different level signal

The Noise Figure of an LNA it will not change with its input level (if the gain of the LNA remain constant, or the LNA do not go in compression).

In receiver NF evaluation, because the gain of various stages change vs input power (due to the AGC) the situation is different.
Blockers (mostly the inband ones) it will make the AGC to reduce the gain of various stages, and indirectly in this situation the receiver (system) NF it will increase.

Hi，Vfone,
Thank you .
When we anticipate the maximum blocking level the receiver can bear,
how to diffrentiate the effect is induced by link compression or by noise from ADC due to change of RF Gain(AGC is controlled)

In principle you are not defining receiver noise figure which is about how many times your receiver generates the thermal noise from a matching resistor source. You want to know signal-to-noise ratio, or, more exactly, signal-to (noise plus interference) ratio.

Injecting interfering signals rarely affects the receiver noise figure, mostly defined by the first receiver stage (low-noise amplifier). It does affect the latter stages where the interfering signal, amplified together with the desired signal, can mix up, create harmonic and in-harmonic combinations which are demodulated together.

The best way to handle unwanted interference is using a good pass-band filter that rejects out-of-band interference. Another idea is to make the receiver linear by using the gain stages that can amplify the signal without limiting; this reduces the probability of creating undesired signal x cross interference combinations.

Using a directional antenna in the receiver is also important if an interferer can come from other than "your" direction.

You can differentiate between NF increase due to AGC, or from noise introduced by ADC, only if you have good knowledge of each stage state (if it is or not in compression, OR gain reduction due to AGC).
As I mentioned, stage gain reduction it will affect the total RF System Noise Figure, as you can see in the Friis equation:
F_total = F1 + ((F2-1)/G1) +((F3-1)/(G1G2))......

Meantime (due to the SNR requirements) the NF of the system has to be minimized at low input levels (high-gain of each stage), mainly from the point where AGC starts reducing gain, called take-over-point. The take-over-point depends by SNR requirements and by applications.