class Model(parl.Model):
    def __init__(self, act_dim):
        hid1_size = 128
        hid2_size = 128
        # 3层全连接网络
        self.fc1 = layers.fc(size=hid1_size, act='relu')
        self.fc2 = layers.fc(size=hid2_size, act='relu')
        self.fc3 = layers.fc(size=act_dim, act=None)
        self.batch_norm = layers.batch_norm() # for example ++++++++++++++++++++++++

    def value(self, obs):
        # 定义网络
        # 输入state，输出所有action对应的Q，[Q(s,a1), Q(s,a2), Q(s,a3)...]
        h1 = self.fc1(obs)
        h2 = self.fc2(h1)
        Q = self.fc3(h2)
        Q = self.batch_norm(Q) # for example ++++++++++++++++++++++++
        return Q

还可以带参数。具体可以看一下这个文件：

parl/core/fluid/layers/layer_wrappers.py

谢谢，昨天在别的地方找到答案了。要注意版本问题，parl.layers.batch_norm要配paddle1.6.1的版本

不客气，问题解决就好。