"The French judicial system was very clear in pointing to evidence that Turkish secret services were involved in this crime," a Communist Party statement said on Tuesday.
Sakine Cansiz, Fidan Dogan and Leyla Seylemez were murdered at a Kurdish cultural centre in Paris in 2013.
The meeting between French President Emmanuel Macron and Erdogan would be "yet another insult to the families of the victims" and to Turkey's Kurdish population, it said.
Erdogan's government broke off peace talks with the Kurdistan Workers' Party (PKK) guerrilla group in 2015, reviving a war that has meant harsh repression the country's south-east.
There has also been a widespread purge of Turkey's military, civil service, media and other sectors after a failed coup attempt in 2016.
About 140,000 people have been fired or suspended from their jobs and more than 55,000 arrested.
Syria, Palestine, refugees
Macron has promised to raise human rights during the visit but appears keener to discuss the Syrian conflict and the situation in Israel and the Palestinian territories.
Turkey, a member of the Nato military alliance, has been an ally to Western nations in the fight against the Islamic State armed group in Syria and has taken in some 800,000 refugees.
Ahead of Friday's visit, Erdogan's spokesman Ibrahim Kalin described France as a "leading ally" and expressed hope that the visit would further boost their alliance.
Relations with EU
The visit will be Erdogan's first to France since the July 15, 2016 coup bid aimed at removing him from power.
Turkey's relations with the European Union, which it has been trying to join for decades, worsened when European leaders criticised the post-coup purge.
But last week Erdogan declared that he wanted to have good relations with the EU and praised Macron, as well as the German leadership, for criticising President Donald Trump's announcement that the US embassy would be moved Jerusalem.
The EU and Ankara were on the same page on the question, he said.
Both France and Turkey hope to lift trade volume that at present stands at 11 billion euros.