diff --git a/ObservationSim/Instrument/Filter.py b/ObservationSim/Instrument/Filter.py
index d02416950904d970585f4873e0183823c99377fa..16ec892191314bbe92637be69a549530069ad439 100755
--- a/ObservationSim/Instrument/Filter.py
+++ b/ObservationSim/Instrument/Filter.py
@@ -40,6 +40,7 @@ class Filter(object):
         self.sky_background = filter_param.param[filter_type][5]
         self.mag_saturation = filter_param.param[filter_type][6]
         self.mag_limiting = filter_param.param[filter_type][7]
+        self.zodical_spec = None
 
     def is_too_bright(self, mag, margin=-2.5):
         return mag <= self.mag_saturation + margin
@@ -114,10 +115,14 @@ class Filter(object):
         sl = Straylight(jtime=jtime, sat_pos=sat_pos, pointing_radec=pointing_radec,sun_pos=sun_pos)
         if self.filter_type in ["GU","GV","GI"]:
             s_pix, spec = sl.calculateStrayLightGrating(grating = self.filter_type.upper())
+            if s_pix>0.8:
+                s_pix = 0.8
             self.sky_background = s_pix
             self.zodical_spec = spec
         elif self.filter_type.lower() in ["nuv","u","g","r","i","z","y"]:
             s_pix = sl.calculateStrayLightFilter(filter=self.filter_type.lower())
+            if s_pix>1:
+                s_pix = 1
             self.sky_background = s_pix
             self.zodical_spec = None
 
diff --git a/ObservationSim/ObservationSim.py b/ObservationSim/ObservationSim.py
index 05e77fc64e71f1fab4db04a2e4aeacd6af612ab8..14bc8b4a56f32ceb3ec518ec428258272ac6e9d0 100755
--- a/ObservationSim/ObservationSim.py
+++ b/ObservationSim/ObservationSim.py
@@ -107,9 +107,10 @@ class Observation(object):
         chip.img.setOrigin(chip.bound.xmin, chip.bound.ymin)
         chip.img.wcs = wcs_fp
 
-        filt.setFilterStrayLightPixel(jtime = pointing.jdt, sat_pos = np.array([pointing.sat_x, pointing.sat_y, pointing.sat_z]), pointing_radec = np.array([pointing.ra,pointing.dec]), sun_pos = np.array([pointing.sun_x,pointing.sun_y,pointing.sun_z]))
+        if self.config["obs_setting"]["enable_straylight_model"]:
+            filt.setFilterStrayLightPixel(jtime = pointing.jdt, sat_pos = np.array([pointing.sat_x, pointing.sat_y, pointing.sat_z]), pointing_radec = np.array([pointing.ra,pointing.dec]), sun_pos = np.array([pointing.sun_x,pointing.sun_y,pointing.sun_z]))
 
-        print("========================sky pix========================\n")
+        print("========================sky pix========================")
         print(filt.sky_background)
 
         if chip.survey_type == "photometric":
diff --git a/config/config_C6.yaml b/config/config_C6.yaml
index c7b089d4c34f8fbe40c92fbbfc07fc3bd19deffd..b68442fe42e5fd329fbd6b3a2b60c71f9744c6b8 100644
--- a/config/config_C6.yaml
+++ b/config/config_C6.yaml
@@ -105,6 +105,9 @@ obs_setting:
   # Whether to enable astrometric modeling
   enable_astrometric_model: True
 
+  # Whether to enable straylight model
+  enable_straylight_model: False
+
   # Cut by saturation magnitude in which band?
   cut_in_band: "z"