除非您当前隐藏了某些信息，否则最好在ModelChoiceField的声明中声明查询集：

class PaymentSelectForm(forms.Form):

    date_from = forms.DateField()
    date_to = forms.DateField()
    website = ModelChoiceField(queryset=Website.objects.all()) 
    paymentmethod = forms.ChoiceField(choices=PAYCODE_CHOICES)

    def __init__(self, *args, **kwargs):
        super(PaymentSelectForm, self).__init__(*args, **kwargs)
        applyClassConfig2FormControl(self)

如果查询集是 dynamic（这里不是），可以初始设置为None，然后在__init__函数中覆盖：

class PaymentSelectForm(forms.Form):

    date_from = forms.DateField()
    date_to = forms.DateField()
    website = ModelChoiceField(queryset=None) 
    paymentmethod = forms.ChoiceField(choices=PAYCODE_CHOICES)

    def __init__(self, *args, **kwargs):
        super(PaymentSelectForm, self).__init__(*args, **kwargs)
        applyClassConfig2FormControl(self)
        self.fields['website'].queryset=Website.objects.all()

但通常情况下，例如queryset依赖于传递给表单的参数，或者依赖于其他表（并且它不能优雅地写入SQL查询）。

使用widget.choices

def __init__(self, *args, **kwargs):
        super(PaymentSelectForm, self).__init__(*args, **kwargs)
        applyClassConfig2FormControl(self) 
        self.fields['website'].widget.choices=(
            (choice.pk, choice) for choice in Website.objects.all()
        )